Trends in Toxicology and Related Sciences

Volume 1, Issue 1, March 2017 Review paper

Page 3

BIO-INSPIRED NANOMATERIALS - A BETTER OPTION FOR

NANOMEDICINE

Carolina Constantin1, Monica Neagu

1,2

1 “Victor Babes” National Institute of Pathology, Immunology Department, Bucharest,

Romania

2 Faculty of Biology, University of Bucharest, Romania

Abstract

Searching for the best option to overcome the known toxicity of nanomaterials, a new domain

has recently raised, namely the area of bio-inspired nanomaterials. Our review tackles some of

the differences that inspired nanomedicine to use materials that mimic/resemble/reproduce the

complexity of biomolecules. The main groups of biomolecules that developed nanomaterials and

their applications in nanomedicine are presented. Established clinical studies using this new

type of nanomaterials and in vivo experimental models that are testing these nanomaterials are

presented as well.

Keywords: nanomedicine, bio-inspired, nanomaterials.

Introduction

Medicine is expanding its fields in the therapeutical approach using, in the last few years,

nanotechnologies mainly in the area of drug carriers and targeting (1).

Current expansions in nanosciences and nanomedicine obviously attract the development

of functional nanomaterials such as carbon nanotubes, fullerenes, metal-nanomaterials,

nanoparticles, supramolecular and even self-assembled nanostructures. Tremendous inquires

inspired by nature's astonishing model delineates two classes of these nanomaterials, namely

biotemplates and biomimics (2).

Corresponding author: Carolina Constantin

E-mail address: caroconstantin@gmail.com

Received: May 4, 2016; accepted: July 8, 2016

Constantin&Neagu

Page 4

For this domain, cross fertilization of several areas is done, thus biology should provide the best

biological solution for a medical application while chemistry and physics help the nano-materials

sciences to accomplish the best bio-inspired nanomaterial (Figure 1). Biotemplates and

biomimetic materials have distinctive physico-chemical characteristics that make them very

appropriate for drug delivery and proteomics applications, real helpers in fundamental

knowledge regarding live cells functioning and for designing of bio-nanostructures, the so called

bio-inspired nanomaterials (3). Owing to the fact that the human biological system is made up of

nanoscale self-assembly biomolecules, stands for the potential biomedical functions of these bio-

inspired nanomaterials. The potential therapeutic applications of nanomaterials strongly relies

first, on the similarity with the cellular proteins size, and secondly, on their additional properties

in terms of shape, chemical composition and surface charge, which allows their intracellular

access both by endocytosis as well as by mechanical manner such as membrane disruption (4).

In biomimicry area, coupling nanostructures with biologics is a current approach for drug

delivery development, in order to improve the biocompatibility and specific targeting of the

diseased tissues. The source of biological material has its own importance for increasing the

systemic tolerance and reducing the potential inflammation. For instance, the nanoparticles,

which functionalized with human leukocyte cellular membrane, have escaped from opsonization

and phagocytosis by macrophages and have shown superior targeting and prolonged systemic

circulation; similar studies were performed with murine leukocytes membranes as shown by

time-lapse microscopy (5).

Owing to their particular size and large specific surface area, nanoparticles may interact

directly with cellular systems being explored in pharmaceuticals to enhance bioavailability of

drugs, for diagnostics, therapy and bio-sensing (6). For instance, nanocarriers based on carbon

nanotubes or metal nanoparticles (SiO2, TiO2, Fe3O4 and γ-Fe2O3) can be suitably designed to

reach the desired targets. Such nanomaterials also represent an important platform for medical

imaging and controlled drug delivery (7).

Nanomedicine& bio-inspired

Page 5

Figure 1. Cross fertilization of several domains in bio-inspired nanomaterials

Nanotechnology approaches were used to explore neural stem cells milieu for brain repair

processes. Nanoscale-engineered structures point out cell recruitment, proliferation and

differentiation to functionally recover damaged areas overcoming the blood-brain barrier in

terms of drug delivery and specific cellular targeting (8). In the field of cancer immunotherapy,

the major hurdles are due to antigen poor immunogenicity, safety issues raised from

conventional systemic delivery and immune system behavior in tumor context. Recently,

nanotechnology-based delivery tools for cancer vaccines encompass multifunctional

nanoparticles, presenting benefits such as targeted delivery of therapeutic agents, specific target

of immune cells, as well as augmenting immune activation through immune-stimulatory

mediators (9).

1. Understanding bio-nanoparticle interface

The protein corona phenomenon is well known in the field of synthetic nanotechnology

and refers to adsorption of biomolecules from a bodily fluid, like plasma, on the nanoparticles

surface, influencing thus, their biological properties. This corona structure could also comprise

immunoglobulins and complement factors in different proportions (10). For example, although

titanium dioxide, silicon dioxide and zinc oxide nanoparticles have similar surface charges in

buffer, there are prone to bound different plasma proteins. Hence, when they enter a biological

system and reach human plasma, they selectively absorb biomolecules, developing the

biomolecular corona on their surface (11).

Constantin&Neagu

Page 6

A recent innovative concept is related to micro-nanoparticles (MNP) designated for

stimulus-responsive controlled drug release in tumor therapy. Their unique structural design

allows a special functional versatility in a complex physiological context (pH, redox potential,

enzymes activation status, combinations of stimuli, etc.). In the category of innovative

nanocarriers for pharmaceutical applications fall peptides and (bio)polymers pH-dependent,

redox-sensitive nanogels and micelles, thermo-, magnetic-, mechanical- or electrical-responsive

MNP, as well as stimuli-responsive graphene nanosheets (12).

Surface modification of nano-particles significantly governs their colloidal stability and

biological behavior. The biological behavior can influence blood circulation durations,

biodistribution, and excretion (13, 14). Thus, hybrids encompassing organic/inorganic

composite/hybrid nanomaterial are of outmost importance. Soybean phospholipid is another bio-

inspiring material, as it is a natural plant’s phospholipid. Soybean phospholipid has very good

biocompatibility and amphiphilicity; moreover it can form a stable biomembrane on the surface

of nanomaterials (15). Recently published, 2016, a “thin-film” approach was reported for

encapsulating soybean phospholipid on the surface of MoS2 nanosheets (MoS2 nanosheet, two-

dimensional transition metal dichalcogenide). MoS2 nanosheets were rendered with colloidal

stability due to surface-anchored soybean phospholipid. All the properties tested in vitro and in

vivo breast cancer experiments proved that this new bio-inspired nano-particle displayed anti-

tumoral effect and enhanced bio-compatibility (16).

Studies related to corona surface modulation in order to specific recognize and target

cancer cells were done in vitro and in vivo with nanoparticles derived from Tobacco mosaic

virus, suggesting a role for protein corona effect through the development of efficient viral-

related nanoparticles formulations (17).

Some biological systems such as spherical viruses serve as pattern for self-assembly

organization, which is based on spontaneous association to form higher order structures (18).

Other biological systems serve as inspiration for nanotechnology, for instance atypical DNA

structures (A-form, Z-form, the triplex, the G-quadruplex, etc.) are explored for designing smart

DNA nanostructures for developing definite targets in diagnosis and disease therapy. In addition,

interactions between DNA and carbon nanomaterials largely open the way for finest molecular

recognition as base for applications of materials science in biomedicine. Thus, single walled

carbon nanotubes could hinder telomerase activity in living cells and carbon quantum dots are

Nanomedicine& bio-inspired

Page 7

able to modulate transition of B-form DNA to Z-form DNA. These provide new insights into the

biological actions of carbon nanomaterials on DNA, attracting new advances in the near future

regarding (nano)biomedical applications (19). Gold nanoparticles represent another recent

approach regarding the comprehension of the physicochemical interactions between inorganic

materials and various biological targets (20). This comes to the idea that, distinct from inorganic

materials, biological systems are finely adapted to respond to their environments by a change in

structure and function. Starting from this knowledge, other studies aim the design and synthesis

of inorganic nanoparticles with configurable surface ligands. These are the so called

"transmutable nanoparticles", where inter-bindings can be programmed in response to specific

(bio)chemical signals in a dynamic way (21).

This highly versatility of nanomaterials in biological environment raises a couple of

legitimate questions: "how would they behave in complex cellular architectures?", "what is the

most appropriate structural form in order to generate a biological response upon request, such as

drug delivery?". Very recently it was proposed that, layer-by-layer, self-assembling of

nanoparticles is an emerging tool to create intelligent nanostructures with high degree of

modularity and compositional heterogeneity through successive deposit of alternately charged

polyelectrolytes onto a colloidal pattern. This method allows the direct incorporation of different

biomolecules inside the multilayers such as nucleic acids, polypeptides, polysaccharides and

proteins (22). Supramolecular soft biomaterials represent another result of the recent advances in

chemistry of the highly selective and non-covalent interactions, allowing the design of

morphologies with controlled size, as carriers in drug delivery field.

The most recent progresses of supramolecular self-assemblies through host-guest

inclusion comprise nanoparticles, micelles, vesicles, hydrogels, as well as various stimuli-

responsive morphology transition materials (23). A schematic representation of biological

materials that can inspire nano-medicine field is depicted in Figure 2.

Constantin&Neagu

Page 8

Carbohydrates

Synthetic glycopolymers

Biosensors

Regenerative medicine materials

DNA

Synthetic polynucleotides

Biosensors

Peptides

Synthetic membrane

translocation signals

Transportors across the cell's

membrane

Proteins

Antibodies conjugated to nanoparticles

Diagnostic, biosensors

Lipids

New generation ionizable lipids

siRNA delivery in therapy

Viruses and bacteria shells

Hybrid nanomaterials

Drug delivery

Biological material

Bio-inspired material

Nanomedicine application

Figure 2. Biological materials that can inspire nanomaterials with application in

nanomedicine

2. Types of bio-inspired nanoparticles

2.1. Encapsulated

Solid lipid nanoparticles loaded with trans-resveratrol (RES) were tested for in vitro

cytotoxicity in HaCat keratinocytes cell line and skin delivery ability. The skin

permeation/retention was evaluated via in vitro tyrosinase inhibitory activity and cytotoxicity

was performed by MTT reduction assay. The authors report that after 24 hrs, up to 45% of the

RES-nanostructure passaged through the skin. In addition, the RES-nanostructure proved to be

non-toxic and to inhibit more effective tyrosinase than kojic acid, a classic inhibitor of this

enzyme. This report suggests that RES-loaded lipid nanoparticles have therapeutic potential in

skin pathology field (24). The “antisense technology” has become a promising genomic

approach in recent years through non-viral gene delivery systems, as solid lipid and chitosan

nanoparticles were developed for improving intercellular delivery of siRNA. The highly efficient

siRNA encapsulation in nanoparticles imprints a new meaning for transfection, as a tool for

targeted delivery (25).

2.2. Carriers

The urgent need for overcoming multidrug resistance in cancer leads to novel provisions

like Q-Graphene, as a carbon based-nanocarrier, for killing drug-resistant lung cancer cells. The

addition of hyaluronic acid and rhodamine B isothiocyanate, for both targeted drug delivery and

Nanomedicine& bio-inspired

Page 9

fluorescence imaging, and doxorubicin loaded as “killer” drug, provide a smart nanoplatform for

tracking and monitoring targeted drug delivery to proficiently eradicate drug-resistant cancer

cells (26).

3. Types of bio-molecules that can lead to nanomaterials

Distinct from conventional inorganic compounds, biological materials have an important

property, namely to adapt their responses to the environment. Peptides, proteins and other

biological molecules have a panel of possibilities for chemical binding, hence their biomolecule

can respond by physiologically altering its structure and function. Recently, using this versatility,

there were published articles about nanoparticles with reconfigurable surface ligands. Due to this

property, inter-particle bonding is dependent on the distinct response to specific chemical

indications from the intended environment (27).

Biomolecules with diverse modifications hold great promise in biomedicine, cancer

therapy and drug delivery. These biomolecules are typically unstable when taken up by cells, as

they are easily digested by enzymes. To address this obstacle, nanomaterials have been

employed as drug carriers or vehicles, which are powerful nanoplatforms for imaging and cancer

treatment, offering great advantages as targeting to a diseased site in order to minimize systemic

toxicity, and the ability to solubilize hydrophobic or labile drugs to improve pharmacokinetics.

Targeted drug delivery can be achieved from a high density of biomolecules that are bound to the

surface of nanomaterials, resulting a high affinity for the targets, high local concentration,

preventing thus degradation by enzymes. Furthermore, biomolecule–nanomaterial conjugates

have been identified to enter cells more easily than free biomolecules and controllable drug

release can then be obtained by a response to a stimulus, such as redox, pH, light, thermal,

enzyme-trigged strategies (28).

Certain biomolecules can often be used for obtaining nanomaterials with special

properties in terms of morphology and size. For instance, ascorbic acid has a mild reducing

ability, facilitating chemical context of nanomaterial synthesis with uncommon morphology such

as silver nanowires and gold nanorods. Some amino acids, like aspartic acid, have also the ability

to act as reducing agents in order to prepare gold nanoplates by “green” synthesis method, as

they do not require additional reducing reactants or surfactants. Amino acids could be used as

agents that prevent nanoparticles from aggregation. Thus, gold nanoparticles with good

Constantin&Neagu

Page 10

dispersion in water were prepared using lysine as both capping and bridging agent. Sugar

modified metal nanoparticles have attracted a wide research interest in producing, for example

silver nanoparticles further used as biosensor for concanavalin A detection. Thus, glucose,

chitosan, mannose or amino-dextran were exploited in different synthesis approaches to produce

metal nanoparticles, for example mannose stabilized gold nanoparticles used as a signal

amplifier in the determination of concanavalin A by quartz crystal microbalance (29).

Figure 3. Targeted drug delivery system for tumour cell. Nanoparticle contains both the

drug and the ligand that trigger specific cell receptors

Similarly, lipid bilayers capped on the nanomaterials possess water solubility, are

biocompatible and offer models to explore biological functions, such as membrane fusion or

interactions between various proteins and cell membranes (30). DNA could act as a self-

assembly assisting agent in nanomaterials designing, by having the main advantage of a well

programmed and controlled intermolecular interaction involving DNA, owing to the well-known

bonds established in the DNA structure. In addition, the DNA sequence can be synthesized by

chemical method and moreover, DNA can be further enzymatically modified in the fabrication

process. Gold nanoparticles can be self-assembled into microscale aggregates with DNA

molecules as linker, and further used as precursors for the gold nanowires with excellent sizes

and electric properties. Peptides and proteins are recently used in obtaining different

Nanomedicine& bio-inspired

Page 11

nanoparticles possessing water solubility and biocompatibility (31).

Especially, proteins could act as innovative bricks due to their complex structures,

helping them in being biotemplates or biomimics retainers. Biotemplates are considered those

cavitands biological structures that could function usually as carriers and serve in construction of

innovative functional nanomaterials (32). Such biotemplates are protein cages who’s interior,

exterior or interface structure could be modulated chemically and genetically and serve for

different bioapproaches, ranging from biomedical to electronic devices construction (33, 34).

Figure 4. The protein structure as biotemplate pattern. Different parts of the protein

structure could be exploited for bioinspired nanomaterials design (Adapted from (2))

4. Nanomaterials in medical applications

Nanomaterials represent promising tools in reversing multi-drug resistance (MDR) effect

in cancer cells. MDR refers to the ability of tumor cells to survive or become resistant to the

treatment of a wide variety of drugs. This MDR effect is one of the major obstacles for the

efficacy of a therapeutic regimen; so one of the most common approaches against MDR is the

development of specific ATP-binding cassette transporter inhibitors, but they are often less

effective, less specific and are associated with toxicity. Therefore, the field of nanomaterials is

expected to provide different tools to fight against cancer, as their sizes are well matched to

Protein structure as a cage

Protein Interface

Protein Interior

Protein Exterior

Chemical ligands

Constantin&Neagu

Page 12

biologic targets located in active cells (35). Nanoparticles (NPs) are usually intended to

specifically deliver the antitumor drug inside the target cells, based on the well-known enhanced

permeability and retention effect displayed by solid tumors, which allows NPs to accumulate,

preferably at the tumor site. This effect represents one of the major advantages of NPs against

MDR machinery. Among NPs described to bypass drug resistance phenomena in tumor cells are

included lipid NPs, polymeric NPs, metal NPs, dendrimers and liposomes in NPs foundation

(36). Nanomaterials could act successful in different vaccine delivery systems. However, the

limited capability to elicit long-lasting and rigorous immune responses is a major challenge in

vaccination field. Some reports have recently indicated that antigen delivery via nanoparticles

formulations (including lipid-based particles, micelles, nanostructures of natural or synthetic

polymers, and even lipid-polymer hybrid nanoparticles) significantly increase vaccines

immunogenicity, owing to either immunostimulatory properties of the nanomaterials or by co-

enclosed of key molecular adjuvants, for instance Toll-like receptor agonists (37). Nanomaterials

gain a certain role in combating cancer, by devising a more versatile diagnostic, and in

therapeutic solutions for various malignancies. Many recent data sustain that nanomaterials are

typically accumulated at a higher concentration at the pathological site by comparison with

common drugs (38), even for “remote” anatomical sites such as brain (39). The optimum size of

nanostructures allow an easy penetration of capillaries and to be taken up by the target tissues;

those of sizes bigger than 100 nm could passively cross and target the diseased anatomic sites.

Besides specific targeting, numerous nanodevices are biocompatible and biodegradable.

Moreover for targeting cancer cells, a developing technology is the application of

multifunctional nanostructures, such as dendrimers or polymeric micelles. These nanodevices

contain together the loaded drug and targeting agents, such as antibodies or ligands, and address

specific receptors, along with MRI contrast agents (40, 41).

5. In vivo experimental models – a step forward to clinical trials

One of the first study reporting in vivo models of bio-inspired nanomaterials was

published almost 10 years ago. Then it was shown that water-soluble synthetic polymers are

good candidates for targeted drug delivery, demonstration that led to the first synthetic polymer-

drug conjugates that entered clinical trials (42). Since then, clinical trials for cancer, diabetes,

AIDS, rheumatoid arthritis, etc. were developed. But until 2016, no polymer-synthetic drug

Nanomedicine& bio-inspired

Page 13

conjugate is approved by FDA, although many of them are undergoing final phase of clinical

trials (43). Polymer conjugates have both properties of macromolecular drugs and the versatility

of tailoring molecular mass and additional chemical groups. Studies published in 2007 have

shown the design of two HPMA [N-(2-hydroxypropyl)methacrylamide] copolymer conjugates

that can carry doxorubicin and these conjugates were the first synthetic polymer-drug conjugates

tested in clinical trials. Since then, several improvements were done. An HPMA copolymer was

designed to combine an endocrine-related drug and a cytostatic in order to enhance the therapy

efficacy. Dendritic structures and biodegradable polymers as drug carriers were again a step

forward (31). Early clinical trials results using HPMA were promising, both safety regulation

was passed and therapy efficacy achieved by these compounds. Then, the same bio-inspired

polymer was clinically tested using paclitaxel or camptothecin but results were unsatisfactory. In

2010, HPMA-copolymer platinates entered Phase II clinical development and conclusions were

not as satisfactory as expected. In spite of the first stage optimism, no polymer-drug conjugate is

now an approved drug (44). The somewhat failure of the clinical trials underlie the importance of

a rational design.

Another area that entered the clinical phases is the domain of polymeric micelles. These

are core-shell type nanoparticles formed through the self-assembly of block copolymers. They

are important players in nano-carriers for anticancer drugs because their size, stability of drug

incorporation and drug release rate can be tailored by designing the constituent block

copolymers. After tests were performed in experimental tumor models, these micelles entered

clinical trials. Pancreatic cancer, glioblastoma and various types of metastases can be triggered

by specially designed polymeric micelles. Moreover, in 2016, the new generation of polymeric

micelles that have smart functionalities such as targetability, environment sensitivity and

imaging property was introduced (45).

Another bio-inspired class of compounds that proved their efficacy in experimental

models are PLGA-PRINT (Poly(lactic-coglycolic) acid-Particle replication in non-wetting

templates) nanoparticles containing docetaxel and antiangiogenic mEZH2 siRNA incorporated

into chitosan nanoparticles. The antitumor effect were studied in vivo mouse model of epithelial

ovarian cancer, using several biomarkers such as proliferation index (Ki67), apoptosis index

(cleaved caspase 3), and microvessel density (CD31). Low doses of this compound induced

tumor reduction. In ovarian cancer cell lines, like HeyA8 and SKOV3ip1, the combination of

Constantin&Neagu

Page 14

PLGA-PRINT-docetaxel and CH-mEZH2 siRNA induced important anti-tumoral effect. The

important results obtained in these preclinical models of ovarian cancer established a good

background for future clinical trials (46).

To achieve the next generation of nanoparticles, several characteristics should be

obtained, such as tumor selectivity, nontoxicity, specific targeting and physiological clearance.

Developing probes meeting these criteria is challenging, requiring comprehensive in vivo

evaluations. Few years ago, an ultra-small cancer-selective silica particle was approved for first-

in-human clinical trial. These particles had an efficient renal clearance, and were subjected to

functionalization for specific tumor targeting. Hence the particle was functionalized with cyclic

arginine-glycine-aspartic acid peptide ligands and radioiodine, and in mouse experimental

models of melanoma, it selectively accumulated in αvβ3 integrin-expressing melanoma. When it

was encapsulated with dyes, real-time detection and imaging could be performed in animal

models. This is a good example of a multimodal platform to be developed in clinical trials (47).

In terms of targeted delivery facing good experimental in vivo model, a skin care

formulation was tested by incorporating microsilver, with nanostructured lipid carriers (NLC).

When testing, this new compound showed, in vivo, a high potential to remove the symptoms of

irritated sensitive skin and atopic dermatitis. The silver ion-nanolipid complex increased the

antimicrobial silver efficacy, by increasing the silver concentration on skin and on bacterial

membranes. Combining the antimicrobial effect with normal skin condition restoration by the

NLC film, has triggered a good clinical outcome of the skin condition (48).

Gene therapy is taking a huge advantage on bio-inspired materials. Non-viral structures

can be designed to deliver nucleic acids and offer unquestionable advantages when compared to

viruses as delivery systems. Comparing viral and non-viral systems, reduced toxicity and

immunogenicity is registered, but it has a less potency to deliver nucleic acids than their viral

counterpart. There are several on-going clinical trials that are focusing on non-viral gene therapy

with results that still need to be published (49).

Another recently developing field in cancer nanomedicine is the nanotechnology that tries

to develop therapeutically viable and physiologically safe materials. A study published in 2015 is

focusing on the development of reactive oxygen species (ROS)-triggering nanoparticles. The

authors have designed mesoporous titanium dioxide popcorn (TiO2 Pops) nanoarchitecture that

has the property to on/off-switch its functionally popping ROS. These TiO2 Pops, distinct to the

Nanomedicine& bio-inspired

Page 15

classical TiO2 nanoparticles, are biocompatible. It is extremely interesting that these TiO2 Pops

can trigger the generation of ROS inducing anticancer effect, until apoptosis is induced in tumor

cells. When comparing them to classical TiO2 nanoparticles, they are inducing six times more

apoptotic mechanisms without affecting the normal cells (50).

6. Conclusions

In the nano-technology domain the designed nanoparticles suffer from poor solubility,

instability in biological medium and low bioavailability. Moreover when applied to

nanomedicine, these structures can have an inaccurate distribution and/or an accumulation that

can induce important side effects. When several sciences cross-interact, such as chemistry,

biology and medicine with nano-technology, new solutions emerge, hence the development of

bio-inspired nanomaterials field. This field enlarges the panel of drug carriers with different

properties and functionalities (1). Various types of functional nanosystems are explored from

carbohydrates that can be tailored to develop nanosensors, to peptides and proteins for specific

transporters of drugs through cells, to entire synthetic viruses and bacteria that are the perfect

drug carriers.

All these bio-inspired nanoparticles can provide both improved drug delivery and

imaging probes. Nanopharmaceuticals field gains a new player through these bio-inspired

materials, by the platforms that are being developed lately. The final goal in nanomedicine is to

realize safe and effective therapy and, if possible, align to the tailor-made drugs in personalized

medicine.

The future lies within bio-inspired nanomaterials because they embed some important

properties, low toxicity, good selectivity, favorable targeting and clearance profiles.

References

1. Ogier J, Arnauld T, Doris E. Recent advances in the field of nanometric drug carriers.

Future Med Chem. 2009, 1(4): 693-711, doi: 10.4155/fmc.09.48.

2. Bhattacharya P, Du D, Lin Y. Bioinspired nanoscale materials for biomedical and energy

applications. J. R. Soc. Interface. 2014, 11: 20131067.

3. Andre R, Tahir MN, Natalio F, Tremel W. Bioinspired synthesis of multifunctional

inorganic and bio-organic hybrid materials. FEBS J. 2012, 279: 1737-1749,

Constantin&Neagu

Page 16

doi:10.1111/j.1742-4658.2012. 08584.x.

4. Nel AE, Madler L, Velegol D, Xia T, Hoek EM, Somasundaran P, Klaessig F, Castranova

V, Thompson M. Understanding biophysicochemical interactions at the nano–bio

interface. Nat. Mater. 2009, 8: 543-557, doi:10.1038/nmat2442.

5. Evangelopoulos M, Parodi A, Martinez JO, Yazdi IK, Cevenini A, van de Ven AL,

Quattrocchi N, Boada C, Taghipour N, Corbo C, Brown BS, Scaria S, Liu X, Ferrari M,

Tasciotti E. Cell source determines the immunological impact of biomimetic

nanoparticles. Biomaterials. 2016, 82: 168-177, doi: 10.1016/j.biomaterials.2015.11.054.

Epub 2015 Dec 2.

6. Uddin I, Venkatachalam S, Mukhopadhyay A, Usmani MA. Nanomaterials in the

Pharmaceuticals: Occurrence, Behaviour and Applications. Curr Pharm Des. 2016,

22(11): 1472-1484.

7. Formoso P, Muzzalupo R, Tavano L, Filpo GD, Nicoletta FP. Nanotechnology for the

Environment and Medicine. Mini Rev Med Chem. 2016, 16(8): 668-675.

8. Santos T, Boto C, Saraiva CM, Bernardino L, Ferreira L. Nanomedicine Approaches to

Modulate Neural Stem Cells in Brain Repair. Trends Biotechnol. 2016, pii: S0167-

7799(16)00036-6, doi: 10.1016/j.tibtech.2016.02.003 [e-pub ahead of print].

9. Saleh T, Shojaosadati SA. Multifunctional nanoparticles for cancer immunotherapy. Hum

Vaccin Immunother. 2016, 22: 1-13 [e-pub ahead of print].

10. Neagu M, Piperigkou Z, Karamanou K, Basak Engin A, Docea AO, Constantin C, Negrei

C, Nikitovic D, Tsatsakis A. Protein bio-corona: critical issue in immune nanotoxicology.

Arch Toxicol. 2016, doi:10.1007/s00204-016-1797-5.

11. Basak Engin A, Neagu M, Golokhvast K, Tsatsakis A - Nanoparticles and Endothelium:

An Update on the Toxicological Interactions. Farmacia. 2015, 63(6): 792-805.

12. Karimi M, Ghasemi A, SahandiZangabad P, Rahighi R, MoosaviBasri SM, Mirshekari H,

Amiri M, Shafaei Pishabad Z, Aslani A, Bozorgomid M, Ghosh D, Beyzavi A, Vaseghi A,

Aref AR, Haghani L, Bahrami S, Hamblin MR. Smart micro/nanoparticles in stimulus-

responsive drug/gene delivery systems. Chem Soc Rev. 2016, 45(5): 1457-1501, doi:

10.1039/c5cs00798d.

13. Wang S, Li X, Chen Y, et al. A facile one-pot synthesis of a two-dimensional MoS2 /Bi2

S3 composite theranostic nanosystem for multi-modality tumor imaging and therapy. Adv

Nanomedicine& bio-inspired

Page 17

Mater. 2015, 27(17): 2775–2782.

14. Mou J, Li P, Liu C, et al. Ultrasmall Cu2–x S nanodots for highly efficient photoacoustic

imaging-guided photothermal therapy. Small. 2015, 11(19): 2275-2283.

15. Kostarelos K, Luckham P, Tadros TF. Addition of block copolymers to liposomes

prepared using soybean lecithin. Effects on formation, stability and the specific

localization of the incorporated surfactants investigated. J Liposome Res. 1995, 5(1): 117-

130;

16. Xiang Li, Yun Gong, Xiaoqian Zhou, Hui Jin, Huanhuan Yan, Shige Wang, Jun Liu.

Facile synthesis of soybean phospholipidencapsulated MoS2 nanosheets for efficient in

vitro and in vivo photothermal regression of breast tumor. Int J Nanomedicine. 2016, 11:

1819–1833.

17. Pitek AS, Wen AM, Shukla S, Steinmetz NF. The Protein Corona of Plant Virus

Nanoparticles Influences their Dispersion Properties, Cellular Interactions, and in vivo

Fates. Small. 2016, 12(13): 1758-1769, doi: 10.1002/smll.201502458; e-pub 2016 Feb 8.

18. Indelicato G, Wahome N, Ringler P, Müller SA, Nieh MP, Burkhard P, Twarock R.

Principles Governing the Self-Assembly of Coiled-Coil Protein Nanoparticles. Biophys

J. 2016, 110(3): 646-660; doi: 10.1016/j.bpj.2015.10.057.

19. Sun H, Ren J, Qu X. Carbon Nanomaterials and DNA: from Molecular Recognition to

Applications. Acc Chem Res. 2016, 49(3): 461-470, doi: 10.1021/acs.accounts.5b00515;

e-pub 2016 Feb 23.

20. Charchar P, Christofferson AJ, Todorova N, Yarovsky I. Understanding and Designing the

Gold-Bio Interface: Insights from Simulations. Small. 2016, Mar 23; doi:

10.1002/smll.201503585; [e-pub ahead of print].

21. Kim Y, Macfarlane RJ, Jones MR, Mirkin CA. Transmutable nanoparticles with

reconfigurable surface ligands. Science. 2016, 351(6273): 579-582, doi:

10.1126/science.aad2212.

22. Correa S, Dreaden EC, Gu L, Hammond PT. Engineering nanolayered particles for

modular drug delivery. J Control Release. 2016, Jan 22.pii: S0168-3659(16)30036-0;doi:

10.1016/j.jconrel.2016.01.040; [e-pub ahead of print].

23. Abdul Karim A, Dou Q, Li Z, Loh XJ. Emerging Supramolecular Therapeutic Carriers

Based on Host-Guest Interactions. Chem Asian J. 2016, Feb 2; doi:

Constantin&Neagu

Page 18

10.1002/asia.201501434, [e-pub ahead of print].

24. Rigon RB, Fachinetti N, Severino P, Santana MH, Chorilli M. Skin Delivery and in Vitro

Biological Evaluation of Trans-Resveratrol-Loaded Solid Lipid Nanoparticles for Skin

Disorder Therapies. Molecules. 2016, 20; 21(1), pii: E116; doi:

10.3390/molecules21010116.

25. Senel G, Büyükköroğlu G, Yazan Y. Solid lipid and chitosan particulate systems for

delivery of siRNA. Pharmazie. 2015, 70(11): 698-705.

26. Luo Y, Cai X, Li H, Lin Y, Du D. Hyaluronic Acid-Modified Multifunctional Q.

Graphene for Targeted Killing of Drug-Resistant Lung Cancer Cells. ACS Appl Mater

Interfaces. 2016, 8(6): 4048-4055, doi: 10.1021/acsami.5b11471; e-pub 2016 Feb 3.

27. Kim Y, Macfarlane RJ, Jones MR, Mirkin CA. Transmutable nanoparticles with

reconfigurable surface ligands. Science. 2016, 351(6273): 579-582, doi:

10.1126/science.aad2212.

28. 28. Wang J, Wang TT, Gao PF, Huang CZ. Biomolecules-conjugated nanomaterials for

targeted cancer therapy. J. Mater. Chem. 2014, B, 2: 8452-8465,

doi: 10.1039/C4TB01263A.

29. Lyu Y-K, Lim K-R, Lee BY, Kim KS, Lee W-Y. Microgravimetric lectin biosensor

based on signal amplification using carbohydrate-stabilized gold nanoparticles. Chem.

Commun. 2008, 4771-4773.

30. Mornet S, Lambert O, Duguet E, Brisson A. The Formation of Supported Lipid Bilayers

on Silica Nanoparticles Revealed by Cryoelectron Microscopy. Nano Lett. 2005, 5: 281-

285.

31. Li Z, Yang T. The Application of Biomolecules in the Preparation of Nanomaterials, In:

"Biomedical Engineering - Frontiers and Challenges". Reza Fazel-Rezai (ed), 2011, doi:

10.5772/21422;

32. Sotiropoulou S, Sierra-Sastre Y, Mark SS, Batt CA. Biotemplated nanostructured

materials. Chem. Mater. 2008, 20: 821-834, doi:10.1021/cm702152a.

33. Uchida M et al. 2007 Biological containers: protein cages as multifunctional

nanoplatforms. Adv. Mater. 2007, 19: 1025–1042, doi:10.1002/adma.200601168.

Nanomedicine& bio-inspired

Page 19

34. Nam KT, Kim D-W, Yoo PJ, Chiang C-Y, Meethong N, Hammond PT, Chiang Y-M,

Belcher AM. Virus enabled synthesis and assembly of nanowires for lithium ion battery

electrodes. Science. 2006, 312: 885–888, doi:10.1126/science.1122716.

35. Conde João, de la Fuente Jesus M, Baptista Pedro V. Nanomaterials for reversion of

multidrug resistance in cancer: a new hope for an old idea? Front Pharmacol. 2013, 4:

134.

36. Dong XW, and Mumper RJ. Nanomedicinal strategies to treat multidrug-resistant tumors:

current progress. Nanomedicine. 2010, 5: 597–615, doi:10.2217/nnm.10.35.

37. Sahdev P, Ochyl LJ, Moon JJ. Biomaterials for Nanoparticle Vaccine Delivery Systems.

Pharm Res. 2014. 31(10): 2563–2582, doi:10.1007/s11095-014-1419-y.

38. Chen PC, Mwakwari SC, Oyelere AK. Gold nanoparticles: from nanomedicine to

nanosensing. Nanotechnol Sci Appl. 2008, 1: 45-66.

39. Muthu MS, Singh S. Targeted nanomedicines: effective treatment modalities for cancer,

AIDS and brain disorders. Nanomedicine. 2009, 4: 105-118.

40. Grossman JH, Scott E, McNei SE. Nanotechnology in cancer medicine. Phys Today.

2012, 65: 38-42.

41. Namiki Y, Fuchigami T, Tada N, Kawamura R, Matsunuma S, Kitamoto Y, Nakagawa

M. Nanomedicine for cancer: lipid-based nanostructures for drug delivery and

monitoring. Acc Chem Res. 2011, 44: 1080-1093.

42. Duncan R. Designing polymer conjugates as lysosomotropic nanomedicines. Biochem

Soc Trans. 2007, 35(Pt 1): 56-60.

43. Singh J, Desai S, Yadav S, Narasimhan B, Kaur H. Polymer Drug conjugates: Recent

Advancements In various Diseases. Curr Pharm Des. 2016. Feb 17; [e-pub ahead of

print].

44. Duncan R, Vicent MJ. Do HPMA copolymer conjugates have a future as clinically useful

nanomedicines? A critical overview of current status and future opportunities. Adv Drug

Deliv Rev. 2010, 62(2): 272-282, doi: 10.1016/j.addr.2009.12.005; e-pub 2009 Dec 11.

45. Nishiyama N, Matsumura Y, Kataoka K. Development of polymeric micelles for

targeting intractable cancers. Cancer Sci. 2016 Apr 26; doi: 10.1111/cas.12960; [e-pub

ahead of print].

Constantin&Neagu

Page 20

46. Gharpure KM, Chu KS, Bowerman CJ, Miyake T, Pradeep S, Mangala SL, Han

HD, Rupaimoole R,Armaiz-Pena GN, Rahhal TB, Wu SY, Luft JC, Napier ME, Lopez-

Berestein G, DeSimone JM, Sood AK. Metronomic docetaxel in

PRINT nanoparticles and EZH2 silencing have synergistic antitumor effect in ovarian

cancer. Mol Cancer Ther. 2014, 13(7): 1750-1757, doi: 10.1158/1535-7163.MCT-13-

0930; e-pub 2014 Apr 22.

47. Benezra M, Penate-Medina O, Zanzonico PB, Schaer D, Ow H, Burns A, De Stanchina

E, Longo V, Herz E,Iyer S, Wolchok J, Larson SM, Wiesner U, Bradbury MS.

Multimodal silica nanoparticles are effective cancer-targeted probes in a model of human

melanoma. J Clin Invest. 2011, 121(7): 2768-2780, doi: 10.1172/JCI45600, e-pub 2011

Jun 13.

48. Keck CM, Schwabe K. Silver-nanolipid complex for application to atopic dermatitis skin:

rheological characterization, in vivo efficiency and theory of action. J Biomed

Nanotechnol. 2009, 5(4): 428-436.

49. Sunshine JC, Bishop CJ, Green JJ. Advances in polymeric and inorganic vectors for

nonviral nucleic acid delivery. Ther Deliv. 2011, 2(4):493-521.

50. Patra HK, Imani R, Jangamreddy JR, Pazoki M, Iglič A, Turner AP, Tiwari A. On/off-

switchable anti-neoplastic nanoarchitecture. Sci Rep. 2015, 5: 14571, doi:

10.1038/srep14571.