Stimuli-Responsive Block Copolymer Micelles Based on Mussel-Inspired Metal-Coordinated Supramolecular Networks.

Amphiphilic diblock copolymers containing dopamine and zwitterions are synthesized via the RAFT polymerization method, which undergo temperature-mediated micellization in aqueous media. The presence of catechol moiety in dopamine is exploited to form pH-responsive cross-links with ferric ions (Fe3+ ) at different pH value. Herein, a comprehensive study of the effect of pH as well as temperature on the size and solution behavior of these cross-linked micelles is presented. These micelles cross-linked via metal-catechol coordination bonds can have several important biomedical applications such as degradable scaffolds for payload delivery.

Graphene Quantum Dots-Ornamented Waterborne Epoxy-Based Fluorescent Adhesive via Reversible Addition-Fragmentation Chain Transfer-Mediated Miniemulsion Polymerization: A Potential Material for Art Conservation.

Epoxy-based adhesives have gotten significant attention in the conservation of antiquities and repair or reconstruction of artifacts due to their excellent adhesion strength. However, it has become hard to detect repaired work in artifacts due to the transparent nature of epoxy-based adhesives. Hence, the making of fluorescent adhesives has become an exciting topic for art conservators. Here, we have synthesized a new kind of waterborne epoxy-based fluorescent adhesive decorated with graphene quantum dots (GQDs) via reversible addition-fragmentation chain transfer (RAFT)-mediated surfactant-free miniemulsion polymerization. In this case, a new block copolymer (BCP), poly(1-vinyl-2-pyrrolidone)-block-poly(glycidyl methacrylate), has been synthesized via surfactant-free RAFT-mediated miniemulsion polymerization using a polymerization-induced self-assembly technique. The GQDs were prepared from citric acid by a hydrothermal process, and this was used for making a fluorescence-active BCP/GQD nanocomposite emulsion. The obtained BCP/GQD nanocomposite adhesive was transparent and showed blue fluorescence under ultraviolet-visible light, indicating the easy detection of its mark on the artifacts. The BCP and BCP/GQD emulsions were applied to adhere ceramic and glass substrates, and their adhesion strength was evaluated by lap shear tests. The BCP/GQDs showed better adhesion strength than the BCP only, indicating better adhesive performance. Additionally, the synthesis process was carried out in aqueous media, indicating the sustainability and environment-friendliness of the process. We believe that this kind of new waterborne epoxy-based fluorescent adhesive will provide a new contrivance among art conservators to repair or reconstruct artifacts.

A dual thermoresponsive and antifouling zwitterionic microgel with pH triggered fluorescent "on-off" core.

A unique, tailor-made, zwitterionic, dual thermoresponsive and fluorescent microgel probe was synthesized via Reversible Addition Fragmentation chain-Transfer (RAFT) polymerization. Microgels were prepared via oil in water (o/w) emulsion polymerization where poly(carboxybetaine) (PCB) acted as a macro-RAFT reagent as well as an emulsifier. The presence of poly(N-vinylcaprolactam) (PNVCL) in the microgel system imparts the thermoresponsiveness to the system and the presence of a rhodamine derivative as fluorophore makes it responsive to pH change of the system by showing a fluorescence emission at 580 nm (reddish orange color). The dual thermoresponsiveness [i.e. the presence of upper critical solution temperature (UCST @ 12 °C) as well as lower critical solution temperature (LCST @ 33 °C)] of the microgels was studied via UV-visible spectroscopy (UV-vis) and temperature responsive dynamic light scattering (DLS) analyses. Presence of the PCB in the corona-crosslinked microgel, played a vital role in the formation of self-assembled structure as well as in protein immobilization (antifouling activity). Antifouling property was studied using UV-vis spectroscopy where bovine serum albumin (BSA) was taken as a model protein. The presence of the pH-responsive fluorescence, thermoresponsiveness as well as antifouling properties makes this zwitterionic microgel system a potential a potential candidate for medical diagnostics and for drug delivery vehicles.

AgNPs Ornamented Modified Bacterial Cellulose Based Self-Healable L-B-L Assembly via a Schiff Base Reaction: A Potential Wound Healing Patch.

A layer-by-layer (L-B-L) bacterial cellulose (BC)-based transdermal patch has been prepared via a Schiff base reaction. The L-B-L assembly consisting of covalently cross-linked ethylene diamine-modified carboxymethylated BC isolated from the Glucanoacetobacter xylinus (MTCC7795) bacterial strain and aldehyde-modified pectin formed via a Schiff base reaction. The presence of the imine bond assists the self-healing process after being scratched in the presence of a pH 7.4 buffer solution monitored via optical microscopy, atomic force microscopy, and tensile strength analyses. The formation of the L-B-L assembly was confirmed using field-emission scanning electron microscopy (FESEM) analysis. Simultaneously, water swelling and deswelling studies were carried out to test its water retention efficiency. The presence of silver nanoparticles (AgNPs) has been confirmed by ultraviolet-visible spectroscopy and FESEM analyses. The antimicrobial activity of the AgNPs-incorporated transdermal patch has been examined over Staphylococcus aureus and Escherichia coli using the zone of inhibition method. Additionally, the cell viability assay was performed using the fluorescent dyes 4',6-diamidino-2-phenylindole and propidium iodide. The AgNPs in the L-B-L assembly showed antimicrobial property against both types of bacteria. The cytotoxicity and wound healing property of the patch system have been studied over NIH 3T3 fibroblast and A549 epithelial cell lines. The L-B-L film also influenced the wound healing process of these two cell lines.

Hydrothermal synthesis of gelatin quantum dots for high-performance biological imaging applications.

In the present study, we are reporting a one-pot synthesis of gelatin quantum dots (GeQDs) by the hydrothermal process. The synthesized GeQDs were characterized by fourier transform infrared spectroscopy, nuclear magnetic resonance, ultraviolet-visible and photoluminescence spectroscopic techniques, and also by using high-resolution transmission electron microscopy. The GeQDs showed a high level of photoluminescence quantum yield (PLQY) with significantly higher stability for up to 6 months and presented similar fluorescent intensity as the initial PLQY without any precipitation and aggregation at ambient condition. The cell imaging ability of synthesized GeQDs was examined using cells belonging to diverse clinical backgrounds like bacterial cells including Escherichia coli and Staphylococcus aureus, yeast cells including Candida albicans, C. krusei, C. parapsilosis, and C. tropicalis, mycelial fungi including Aspergillus flavus and A. fumigatus cells, cancer cell lines A549, HEK293 and L929. The results demonstrated that the GeQDs illuminates the cells and can be utilized as potential cell labeling non-toxic biomarkers. In conclusion, it can be said that the gelatin stabilized QDs are a promising candidate for stable and long-term fluorescent imaging of different types of cells.

Glycopolymer ornamented octa-arm POSS based organic-inorganic hybrid star block copolymer as a lectin binding ligand.

In this study, a polyhedral oligomeric silsesquioxane-polycaprolactone (POSS-PCL)-cored octa-arm star-shaped glyco block copolymer (BCP), poly(ε-caprolactone)-b-poly(glucopyranose) (Star-POSS-PCL-b-PGlc) was successfully synthesized via the combination of ring opening polymerization (ROP) and MADIX (macromolecular design by interchange of xanthate) polymerization technique. Herein, initially octa(3-hydroxy-3-methylbutyl dimethylsiloxy) POSS (Star-POSS) was utilized to initiate the ROP of the ε-caprolactone to get octa-arm star-shaped Star-POSS-PCL. A successive bromination followed by xanthation of the synthesized Star-POSS-PCL polymer allowed us to further polymerize 3-O-acryloyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose (AIpGlc) via MADIX polymerization. Formation of the star-shaped block copolymer (BCP) was characterized using 1H NMR, FT-IR and DSC analyses. The morphology and the aqueous solution behavior of the Star-POSS-PCL-b-PGlc were analyzed using FESEM, HRTEM and DLS analyses, respectively. The lectin-binding efficiency of the star-shaped BCP having different glycopolymer block length was studied using turbidimetry assay and fluorescence quenching titration (FQT) using photoluminescence spectroscopy (PL). Here, FITC labeled concanavalin A (FITC-Con A) was used as a model lectin. The cytotoxicity study of the star-shaped BCPs over the human fibroblast cells revealed the non-toxic nature of the BCPs which open up its great potential towards drug delivery vector.

A self-healable and antifouling hydrogel based on PDMS centered ABA tri-block copolymer polymersomes: a potential material for therapeutic contact lenses.

Herein we have prepared an antifouling and self-healable poly(dimethyl siloxane) (PDMS) based hydrogel which consists of a mixture of curcumin loaded zwitterionic PDMS polymersomes and amine functionalized PDMS polymersomes prepared via Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization and a Schiff-base reaction. The curcumin loaded polymersome consists of a PDMS and poly([dimethyl-[3-(2-methyl-acryloylamino)-propyl]-(3-sulfopropyl)ammonium)] (poly(sulfobetaine)) based tri-block copolymer (BCP) and it was characterized by dynamic light scattering (DLS), high resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) analyses. To prepare the hydrogel, amine functionalized PDMS polymersomes were crosslinked with polyethylene glycol dialdehyde (PEG-DA) in pH 7.4 buffer solution via a Schiff-base reaction. This hydrogel was able to show sustained delivery of the entrapped curcumin drug for more than 72 h. The self-healing characteristic of the prepared hydrogel in the presence of saline water was elucidated by the "scratch and heal" method and subsequently analyzed through tensile study. Due to the presence of the poly(zwitterionic) moiety in the hydrogel system, it was observed that the hydrogel can efficiently reduce protein deposition, where Bovine Serum Albumin (BSA) was taken as a model protein. It was observed that the curcumin loaded hydrogel was detrimental towards both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. This type of smart soft hydrogel system can be a potential material for therapeutic applications for several eye diseases.

Smart Polyacrylate Emulsion Based on a New ABC-Type Triblock Copolymer via RAFT-Mediated Surfactant-Free Miniemulsion Polymerization: Its Multifunctional Properties.

The present investigation deals with the development of an acrylic-based polymeric emulsion that offers multifunctional properties such as superhydrophobic, antimicrobial, anti-icing, and self-cleaning. The said multifunctional waterborne emulsion was prepared via a surfactant-free reversible addition-fragmentation chain transfer (RAFT) polymerization technique. To accomplish this, a new class of ABC-type triblock copolymer (PMTAC-b-PBA-b-PIBA) based on 2-(methacryloyloxy) ethyl ammonium chloride (MTAC), n-butyl acrylate, and isobornyl acrylate (IBA) was synthesized via a polymerization-induced self-assembly technique in a surfactant-free miniemulsion process. The cationic polymer PMTAC was used as a macro-RAFT agent to prepare the rest of the blocks in the presence of nanosize monodisperse colloidal silica particles, leading to a raspberry-like morphology via ionic interaction between anionic silica particles and the cationic block copolymer (BCP). A water contact angle of more than 150° was achieved for the emulsion coating after the fluorosilane treatment which delineates its superhydrophobic nature. The prepared emulsion showed antimicrobial property both in Gram-positive  (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The resultant BCP emulsion was coated over different substrates like glass, paper, and cotton, and the coating material showed anti-icing and self-cleaning properties.

REDOX Responsive Fluorescence Active Glycopolymer Based Nanogel: A Potential Material for Targeted Anticancer Drug Delivery.

A well-defined glycopolymer based fluorescence active nanogel has been prepared via the combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and Diels-Alder (DA) "click" chemistry. To prepare the nanogel, initially, a functional AB block copolymer (BCP) poly(pentafluorophenyl acrylate)-b-poly(furfuryl methacrylate) (PPFPA-b-PFMA), having activated pentafluorophenyl ester group, was synthesized via RAFT polymerization. The activated pentafluorophenyl functionality was replaced by the amine functionality of glucosamine to introduce the amphiphilic BCP poly[2-(acrylamido) glucopyranose]-b-poly(furfuryl methacrylate) (PAG-b-PFMA). Furthermore, the terminal acid (-COOH) functionality of the RAFT agent was modified by gelatin QDs (GQDs) to generate fluorescence active glycopolymer. An anticancer drug, Doxorubicin, was loaded in the micelle via the successive addition of the drug molecule and cross-linking using dithio-bismaleimidoethane (DTME), a REDOX responsive cross-linker. The anticancer activity of the drug loaded nanogel was observed over MBA-MD-231, human breast cancer cell line, and monitored via fluorescence spectroscopy and flow cytometric analyses (FACS). The cytotoxicity of the prepared glycopolymer based nanogel over the MBA-MD-231 cell line was assessed via MTT assay test, and it was observed that the synthesized nanogel was noncytotoxic in nature.

A muscle mimetic polyelectrolyte-nanoclay organic-inorganic hybrid hydrogel: its self-healing, shape-memory and actuation properties.

In this investigation, we report a non-covalent (ionic interlocking and hydrogen bonding) strategy of self-healing in a covalently crosslinked organic-inorganic hybrid nanocomposite hydrogel, with specific emphasis on tuning its properties fitting into a muscle mimetic material. The hydrogel was prepared via an in situ free radical polymerization of sodium acrylate (SA) and successive crosslinking in the presence of starch grafted with poly(2-(methacryloyloxy)ethyl trimethyl ammonium chloride) (PMTAC) and montmorillonite modified with cetyl ammonium bromide (OMMT). This hydrogel shows stimuli triggered self-healing following damage in both neutral and acidic solutions (pH = 7.4 and pH = 1.2). This behavior was reported using stress-strain experiments and rheological analyses of the hydrogel segments joined at their fracture points. The hydrogel was also able to display shape memory properties in the presence of water as well as stimuli (salt, acid and electric impulse) driven actuation behavior. It was observed that the ultimate tensile strength (UTS) of the self-healed hydrogel at pH = 7.4 was comparable to the extensor digitorum longus (EDL) muscle of a New Zealand white rabbit and the as synthesized self-healable hydrogel was found to be non-cytotoxic against NIH 3T3 fibroblast cells.

Curcumin entrapped gelatin/ionically modified bacterial cellulose based self-healable hydrogel film: An eco-friendly sustainable synthesis method of wound healing patch.

In this context, we have prepared a biocompatible gelatin based polyelectrolyte hydrogel patch that has an inherent ability to self-heal in the presence of physiological pH (pH = 7.4). The gelatin-based hydrogel patch consists of the ionically modified self-assembled bacterial cellulose (iBC), extracted from Glucanoacetobacter xylinus (MTCC7795) bacterial strain. Presence of the iBC provides a sturdy cage to the gelatin matrix and also participates into the self-healing activity via formation of the ionic interlocking system in the presence of buffer solution having a pH of 7.4 after being damaged. The self-healing activity of the patch has been monitored through tensile strength measurement and AFM depth profilometry analyses. Loading of the curcumin in the hydrogel patch system incorporates the wound healing activity, examined over the NIH 3 T3 fibroblast cell line. The patch is also able to show antimicrobial activity which has been assessed via FESEM analysis and live-dead assay using propidium iodide (PI) and 4',6-diamidino-2-phenylindole (DAPI) as a fluorescent indicator. This self-healable, ionically interlocked, mechanically robust, bio-derived smart hydrogel patch system can pave a new direction in the transdermal drug delivery system.

Self-Healable Antifouling Zwitterionic Hydrogel Based on Synergistic Phototriggered Dynamic Disulfide Metathesis Reaction and Ionic Interaction.

A self-healable antifouling hydrogel based on zwitterionic block copolymer was prepared via reversible addition-fragmentation chain transfer polymerization and Diels-Alder "click" chemistry. The hydrogel consists of a core-cross-linked zwitterionic block copolymer having poly(furfuryl methacrylate) as core and poly(dimethyl-[3-(2-methyl-acryloylamino)-propyl]-(3-sulfopropyl)ammonium) (poly(sulfobetaine)) as shell. The core was cross-linked with dithiobismaleimidoethane. The block copolymers were characterized by dynamic light scattering, field emission scanning electron microscopy, high-resolution transmission electron microscopy, atomic force microscopy (AFM), differential scanning calorimetry, water contact angle, and small-angle X-ray scattering analyses. This zwitterionic hydrogel showed self-healing activity via combined effect of phototriggered dynamic disulfide metathesis reaction and zwitterionic interaction, which was monitored by optical microscopy and AFM depth profilometry. The mechanical properties of the hydrogel before and after self-healing were studied using depth-sensing nanoindentation method. It was observed that the prepared zwitterionic hydrogel could reduce the formation of biofilm, which was established by studying the bovine serum albumin (model protein) adsorption over the coating. This multifunctional hydrogel can pave a new direction in antifouling self-healable gel coating applications.

Organically modified clay supported chitosan/hydroxyapatite-zinc oxide nanocomposites with enhanced mechanical and biological properties for the application in bone tissue engineering.

The objective of this study is to design biomimetic organically modified montmorillonite clay (OMMT) supported chitosan/hydroxyapatite-zinc oxide (CTS/HAP-ZnO) nanocomposites (ZnCMH I-III) with improved mechanical and biological properties compared to previously reported CTS/OMMT/HAP composite. Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to analyze the composition and surface morphology of the prepared nanocomposites. Strong antibacterial properties against both Gram-positive and Gram-negative bacterial strains were established for ZnCMH I-III. pH and blood compatibility study revealed that ZnCMH I-III should be nontoxic to the human body. Cytocompatibility of these nanocomposites with human osteoblastic MG-63 cells was also established. Experimental findings suggest that addition of 5wt% of OMMT into CTS/HAP-ZnO (ZnCMH I) gives the best mechanical strength and water absorption capacity. Addition of 0.1wt% of ZnO nanoparticles into CTS-OMMT-HAP significantly enhanced the tensile strengths of ZnCMH I-III compared to previously reported CTS-OMMT-HAP composite. In absence of OMMT, control sample (ZnCH) also showed reduced tensile strength, antibacterial effect and cytocompatibility with osteoblastic cell compared to ZnCMH I. Considering all of the above-mentioned studies, it can be proposed that ZnCMH I nanocomposite has a great potential to be applied in bone tissue engineering.

A new class of dual responsive self-healable hydrogels based on a core crosslinked ionic block copolymer micelle prepared via RAFT polymerization and Diels-Alder "click" chemistry.

Amphiphilic diblock copolymers of poly(furfuryl methacrylate) (PFMA) with cationic poly(2-(methacryloyloxy)ethyltrimethyl ammonium chloride) (PFMA-b-PMTAC) and anionic poly(sodium 4-vinylbenzenesulfonate) (PFMA-b-PSS) were prepared via reversible addition fragmentation chain-transfer (RAFT) polymerization by using PFMA as a macro-RAFT agent. The formation of the block copolymer was confirmed by FTIR and 1H NMR analyses. In water, the amphiphilic diblock copolymers, (PFMA-b-PMTAC) and (PFMA-b-PSS), formed micelles with PFMA in the core and the rest of the hydrophilic polymers like PMTAC and PSS in the corona. The PFMA core was crosslinked by using Diels-Alder (DA) "Click" chemistry in water at 60 °C where bismaleimide acted as a crosslinker. Afterwards, both the core crosslinked micelles were mixed at an almost equal charge ratio which was determined by zeta potential analysis to prepare the self-assembled hydrogel. The de-crosslinking of the hydrophobic PFMA core in the self-assembled hydrogel via rDA reaction took place at 165 °C as determined from DSC analysis. This hydrogel showed self-healing behavior using ionic interaction (in the presence of water) and DA chemistry (in the presence of heat).

Modified bacterial cellulose based self-healable polyeloctrolyte film for wound dressing application.

In this investigation, we prepare a self-healable polyelectrolyte film via crosslinking the cationically charged chitosan (Cts) with anionically modified bacterial cellulose (BC), which is a green source of nano-filler. This polyelectrolyte film is able to show dynamic self-healing activity at physiological pH condition via adapting ionic interaction, a state of non-covalent bond. BC was prepared using Glucanoacetobacter xylinus (MTCC7795) bacteria and after that its surface was modified with anionic poly(acrylic acid) using "grafting from" technique. It was observed that the notch (single and multiple) created over the composite film was disappeared by showing vibrant diffusion and ionic interlocking in contact with buffer solution having physiological pH. The XTT assay revealed that the composite film is non-toxic in nature and it was witnessed that the composite film was capable of delivering curcumin, a hydrophobic drug that has an ability to show antimicrobial activity and wound healing capability.

Multifunctional zirconium oxide doped chitosan based hybrid nanocomposites as bone tissue engineering materials.

This paper reports the development of multifunctional zirconium oxide (ZrO2) doped nancomposites having chitosan (CTS), organically modified montmorillonite (OMMT) and nano-hydroxyapatite (HAP). Formation of these nanocomposites was confirmed by various characterization techniques such as Fourier transform infrared spectroscopy and powder X-ray diffraction. Scanning electron microscopy images revealed uniform distribution of OMMT and nano-HAP-ZrO2 into CTS matrix. Powder XRD study and TEM study revealed that OMMT has partially exfoliated into the polymer matrix. Enhanced mechanical properties in comparison to the reported literature were obtained after the addition of ZrO2 nanoparticle into the nanocomposites. In rheological measurements, CMZH I-III exhibited greater storage modulus (G') than loss modulus (G″). TGA results showed that these nanocomposites are thermally more stable compare to pure CTS film. Strong antibacterial zone of inhibition and the lowest minimum inhibition concentration (MIC) value of these nanocomposites against bacterial strains proved that these materials have the ability to prevent bacterial infection in orthopedic implants. Compatibility of these nanocomposites with pH and blood of human body was established. It was observed from the swelling study that the swelling percentage was increased with decreasing the hydrophobic OMMT content. Human osteoblastic MG-63 cell proliferations were observed on the nanocomposites and cytocompatibility of these nanocomposites was also established. Moreover, addition of 5wt% OMMT and 5wt% nano-HAP-ZrO2 into 90wt% CTS matrix provides maximum tensile strength, storage modulus, aqueous swelling and cytocompatibility along with strong antibacterial effect, pH and erythrocyte compatibility.

Modified chitosan encapsulated core-shell Ag Nps for superior antimicrobial and anticancer activity.

This investigation reports a one pot synthesis of silver nanoparticles (Ag Nps) using aqueous solution of chitosan-graft-poly(acrylamide) (Cts-g-PAAm) as a reducing agent and polyethylene glycol (PEG) as a stabilizing agent. The as synthesized Ag Nps was characterized by ultra violet-visible (UV-vis), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis. Field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that Ag Nps, which were stable upto more than 60 days, were spherical in shape and the particle size was in the range of 5-50 nm. Atomic force microscopy (AFM) image also supported the above obtained result. The prepared Ag Nps exhibited strong antimicrobial activity against different gram positive bacteria (Alkaliphilus, Bascillus substillis, Lysinibascillus) and gram negative bacteria (Enterobacter aerogenus, Vivbrio vulnificus and Escherichia coli) and haemolytic assay revealed its blood compatible nature. The synthesized Ag Nps showed significant cytotoxicity over human cervical HeLa cancer cells and it was found that the inhibitory concentration for 50% cell death (IC50) was 8 µg/ml.

Biofunctionalized surface-modified silver nanoparticles for gene delivery.

Silver nanoparticles (AgNPs) find use in different biomedical applications including wound healing and cancer. We propose that the efficacy of the nanoparticles can be further augmented by using these particles for gene delivery applications. The objective of this work was to engineer biofunctionalized stable AgNPs with good DNA binding ability for efficient transfection and minimal toxicity. Herein, we report on the one-pot facile green synthesis of polyethylene glycol (PEG) stabilized chitosan-g-polyacrylamide modified AgNPs. The size of the PEG stabilized AgNPs was 38 ± 4 nm with a tighter size distribution compared to the unstabilized nanoparticles which showed bimodal distribution of particle sizes of 68 ± 5 nm and 7 ± 4 nm. To enhance the efficiency of gene transfection, the Arg-Gly-Asp-Ser (RGDS) peptide was immobilized on the silver nanoparticles. The transfection efficiency of AgNPs increased significantly after immobilization of the RGDS peptide reaching up to 42 ± 4% and 30 ± 3% in HeLa and A549 cells, respectively, and significantly higher than 34 ± 3% and 23 ± 2%, respectively, with the use of polyethyleneimine (25 kDa). These nanoparticles were found to induce minimal cellular toxicity. Differences in cellular uptake mechanisms with RGDS immobilization resulting in improved efficiency are elucidated. This study presents biofunctionalized AgNPs for potential use as efficient nonviral carriers for gene delivery with minimal cytotoxicity toward augmenting the therapeutic efficacy of AgNPs used in different biomedical products.