Lanolin‐based organogels as a matrix for topical drug delivery

The current study deals with the development of lanolin‐based emulsion gels by hot emulsification method. Bright‐field, phase contrast, and fluorescent micrographs of the gels have shown the uniform distribution of circular water droplets in the formulations. Coalescence of water droplets was observed in gels containing higher proportion of water. Fourier transform infrared spectrophotometric studies indicated absence of Ln‐drug chemical interactions. X‐ray diffraction studies suggested an increase in amorphousness of the gels with the incorporation of water into the gel structure. The salicylic acid (SA), model drug, release from the gels was found to follow Higuchi kinetics. Krossmeyer–Peppas model fitting indicated non‐Fickian release of the drug. As the water content of the gels increased, there was a corresponding increase in the rate of release of the drug. The gels showed non‐Newtonian and thixotropic flow behavior. The gel to sol transition and melting temperatures of the gels were identified by differential scanning calorimetric (DSC) thermal analysis and falling ball method. DSC thermograms indicated an increase in thermal stability with the increase of water content in the gels. The gels showed sufficient spreadability and biocompatibility characteristics to be used as topical formulations. SA loaded gels showed good antimicrobial efficacy against Bacillus subtilis, a Gram‐positive bacterium. Based on the preliminary studies, the developed gels may be regarded as carriers in topical drug delivery. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

β‐cyclodextrin‐conjugated hyaluronan hydrogel as a potential drug sustained delivery carrier for wound healing

In order to develop a potential drug sustained delivery carrier suitable for wound healing, a series of β‐cyclodextrin conjugated hyaluronan hydrogels (β‐CD‐HA) with adjustable crosslink densities were synthesized and characterized, meanwhile the delivery kinetics and mechanism of diclofenac as a model anti‐inflammatory drug from these hydrogels were investigated. By controlling the feeding molar ratio of β‐CD/HA, a β‐CD substitution degree of 4.65% was obtained by ¹H‐NMR analysis. The incorporation of β‐CD modification had little effect on the internal porous structure, water swelling ratio, and rheological property of HA hydrogel, which however were influenced by the crosslink density. Although the crosslink density had an influence on the drug loading and release profile by altering the water swelling property, the interaction between β‐CD and drug was the primary factor for the high loading capacity and long‐term sustained delivery of diclofenac. The semiempirical equation fit showed that the release of diclofenac from HA‐based hydrogels followed a pseudo‐Fickian diffusion mechanism. By the aid of β‐CD and controlled crosslink density, a β‐CD‐HA hydrogel with a diclofenac sustained delivery period of over 28 days and desirable physicochemical properties was achieved, which will be a promising drug sustained delivery carrier for wound healing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43072.     

Pluronic‐based dual‐stimuli sensitive polymers capable of thermal gelation and pH‐dependent degradation for in situ biomedical application

Thermo‐sensitive hydrogels are considered ideal for applications in the biomedical fields for their biocompatibility, flexibility, tissue‐like water content, and reversible gelation property. By adjusting sufficient hydrophilic–hydrophobic balance in block copolymer structure, thermogel's critical gelation temperature (CGT) can be modified to be near the physiological temperature, which makes it an appealing candidate for in situ gel depot. In this study, we report successful syntheses of novel multiple block copolymer compounds, denoted as dual‐stimuli sensitive polymers (DSSPs), by copolymerizing Pluronic P104 (7100 Da) and 2,2‐bis(aminoethoxy)propane (BAP) using diisocyanate linkers, l ‐lysine ethyl ester diisocyanate (DSSP‐1), and 1,6‐hexamethylene diisocyanate (DSSP‐2). Through effective elongation of polymer chain lengths (DSSP‐1: 41,760 Da, DSSP‐2: 41,230 Da), Pluronic P104's reversible thermal gelation properties were enhanced, as demonstrated by lowered CGTs (DSSP‐1: 36 °C, DSSP‐2: 38.7 °C; 15 wt %) that is near the physiological temperature. Furthermore, integration of acid‐labile BAP allowed rapid pH‐dependent degradation of the polymer, which was displayed by gel permeation chromatography and release profiles of nile red and irinotecan from polymeric micelles and gels, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46552.     

Peas starch‐based film coatings for site‐specific drug delivery to the colon

Peas starch : ethylcellulose‐based film coatings are proposed allowing for site‐specific drug delivery to the colon of inflammatory bowel disease patients. The film coatings are poorly permeable for 5‐aminosalicylic acid in media simulating the contents of the stomach and small intestine. Thus, they can minimize premature drug release in the upper gastrointestinal tract and subsequent absorption into the blood stream. However, once the colon is reached, drug release sets on and is time controlled. This can be attributed to the partial degradation of the peas starch by enzymes secreted by bacteria, which are preferentially present in the colon. Thus, the drug is released at the site of action, which is likely to minimize undesired side effects in the healthy part of the human body and to optimize the therapeutic efficacy of the treatment. A blend ratio of 1 : 4 peas starch : ethylcellulose and a coating level of 15% (w/w) seem to be optimal for pellet coating. Importantly, the polymeric films can be expected to withstand the mechanical stress encountered in vivo because of the motility of the stomach and small intestine. Furthermore, the systems are long‐term stable: drug release from coated pellets remains unaltered during 1‐year open storage. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Biomineralized hyaluronic acid/poly(vinylphosphonic acid) hydrogel for bone tissue regeneration

Novel biomineralized hydrogels composed of hyaluronic acid (HA) and vinyl phosphonic acid (VPAc) were designed with the aim of developing a biomimetic hydrogel system to improve bone regeneration by local delivery of a protein drug including bone morphogenetic proteins. We synthesized crosslinked hydrogels composed of methacrylated HA and poly(VPAc) [P(VPAc)], which serves as a binding site for calcium ions during the mineralization process. The HA/P(VPAc) hydrogels were biomineralized by a urea‐mediation method to create functional polymer hydrogels that can deliver the protein drug and mimic the bone extracellular matrix. The water content of the hydrogels was influenced by the HA/P(VPAc) composition, crosslinking density, biomineralization, and ionic strength of the swelling media. All HA/P(VPAc) hydrogels maintained more than 84% water content. Enzymatic degradation of HA/P(VPAc) hydrogels was dependent on the concentration of hyaluronidase and the crosslinking density of the polymer network within the hydrogel. In addition, the release behavior of bovine serum albumin from the HA/PVPAc hydrogels was mainly influenced by the drug loading content, water content, and biomineralization of the hydrogels. In a cytotoxicity study, the HA/P(VPAc) and biomineralized HA/P(VPAc) hydrogels did not significantly affect cell viability. These results suggest that biomineralized HA/P(VPAc) hydrogels can be tailored to create a biomimetic hydrogel system that promotes bone tissue repair and regeneration by local delivery of protein drugs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41194.     

Biodegradable polymeric injectable implants for long‐term delivery of contraceptive drugs

Development of injectable, long‐lasting, contraceptive drug delivery formulations, and implants are highly desired to avoid unplanned pregnancies while improving patient compliance and reducing adverse side effects and treatment costs. The present study reports on the fabrication and characterization of two levonorgestrel (LNG) microsphere injectable formulations. Poly(?‐caprolactone) (PCL) with 12.5% and 24% (w/w) LNG were fabricated into microspheres, measuring 300 ± 125 µm, via the oil‐in‐water (o/w) emulsion solvent evaporation technique. Formulations showed sustained drug release up to 120 days. FTIR, XRD, DSC, and TGA confirmed the absence of LNG chemical interaction with PCL as well as its molecular level distribution. The in vitro release of LNG was calculated to be Fickian diffusion controlled and properly characterized. The inclusion of multiple elevated release temperatures allowed for the application of the Arrhenius model to calculate drug release constants and representative sampling intervals, demonstrating the use of elevated temperatures for accelerated‐time drug release studies. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46068.     

Chitosan‐based wet‐spun scaffolds for bioactive agent delivery

Use of scaffolds both as supporting materials at defect site and delivery vehicles for bioactive agents is a commonly employed strategy to aid in tissue repair and regeneration. In this study, fibrous meshes of chitosan were prepared by wet spinning and coated with alginate. BSA as a model protein and gentamicin as a model antibiotic were incorporated into the scaffolds in multiple loading models and their release kinetics were studied. The effects of structural form of scaffold and properties of bioactive agents on release profiles were evaluated. Our results suggest that, designed scaffolds are potential candidates for tissue engineering with the feature of controlled bioactive agent delivery. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3759–3769, 2013     

Effects of drug and polymer molecular weight on drug release from PLGA‐mPEG microspheres

This study investigated the effects of drug and polymer molecular weight on release kinetics from poly (g ‐co‐glycolic acid)‐methoxypoly(ethyleneglycol) (PLGA‐mPEG) microspheres. Bovine serum albumin (BSA, 66 kDa), lysozyme (LZ, 13.4 kDa), and vancomycin (VM, 1.45 kDa) were employed as the model drugs, and encapsulated in PLGA‐mPEG microspheres of different molecular weight. Release of macromolecular BSA was mainly dependent on diffusion of drug at/ near the surface of the matrix initially and dependent on degradation of matrix at later stages, while, the small drug of vancomycin seemed to depend totally on diffusion for the duration of the release study. The release behavior of lysozyme was similar to bovine serum albumin, except a shorter lag period. PLGA‐mPEG molecular weight also affected the release behavior of bovine serum albumin and lysozyme, but not obviously. PLGA‐mPEG microspheres in smaller molecular weight seemed to degrade more quickly to obtain a mass lose and matrix erosion, and thus, an accelerated release rate of bovine serum albumin and lysozyme. Vancomycin released much faster than bovine serum albumin and lysozyme, and exhibited no lag period, as it is thought to be diffusion‐controlled. Besides, vancomycin showed no difference in release behavior as PLGA‐mPEG molecular weight change. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41431.     

A rechargeable drug delivery system based on pNIPAM hydrogel for the local release of curcumin

This study was designed to develop a drug delivery system based on poly(N-isopropylacrylamide) (pNIPAM) hydrogel and a suitable solvent to enhance solubility and local release of curcumin. pNIPAM hydrogel was synthesized by radical polymerization. The chemical, mechanical and physical properties and biocompatibility of pNIPAM hydrogel were investigated as an implantable and rechargeable drug reservoir. Curcumin was loaded within pNIPAM hydrogel during swelling by using two different solvents; methanol, an organic solvent, and low molecular weight polyethylene glycol (PEG200), a polymeric solvent. The results of drug solubility showed that using PEG200 can increase curcumin solubility more than commonly used organic solvents such as methanol. Also, the release profile of drug-loaded hydrogels demonstrated that PEG200 has a superior effect on the cumulative amount of released curcumin (33.163 ± 0.319 μg/ml) compared to methanol (8.765 ± 0.544 μg/ml) during 1 week. Based on our results, curcumin-loaded hydrogels did not show any cytotoxicity, and pNIPAM/PEG combination represented an antibacterial effect within 12 hours. Accordingly, it can be concluded that pNIPAM hydrogel in combination with low molecular weight PEG200 could be used as an efficient drug delivery system to preserve and provide sustained release of curcumin as a hydrophobic drug.     

Polyvinyl alcohol‐polyethylene oxide‐carboxymethyl cellulose membranes for drug delivery

The purpose of this research was to develop blends of poly(vinyl alcohol) (PVA)‐poly(ethylene oxide) (PEO) and carboxymethyl cellulose (CMC) by two approaches: solvent casting and freeze‐drying to develop membranes for various biomedical applications. The PVA/PEO/CMC blends in different compositions of 90/10/20, 80/20/20, 70/30/20, 60/40/20, and 50/50/20 were prepared and were coated on polyester (PET) nonwoven fabric and were subsequently freeze‐dried (FD). The influence of PEO concentration on the blend membranes was investigated and characterized by X‐ray diffraction (XRD), differential scanning calorimetry, and attenuated total reflectance‐fourier transform infra‐red (ATR–FTIR) techniques. The water vapor transmission rate (WVTR), swelling behavior, and surface morphology of the FD membranes was also investigated. It was observed that an increase of PEO concentration in blends makes the membranes more fragile. However, the coating of this blend on PET fabric helps in developing the stable membrane. Swelling of the membranes decreased with the increase in the PEO concentration. XRD showed decrease in crystallinity with increase in concentration of PEO. Morphological studies showed a highly porous structure with interconnected pores. The total porosity of the membranes was found to be in the range 89–92%. The FD membranes were found to have WVTR in the range 2000–3000 g/m²/day. A model drug, ciprofloxacin hydrochloride was also incorporated in the matrix and drug release was studied. The antimicrobial nature of the membranes was monitored against E. coli by zone of inhibition method. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Design and evaluation of a lyophilized liposomal gel of an antiviral drug for intravaginal delivery

Liposomes of antiviral drug(acyclovir) prepared by rotary evaporation method were incorporated into two bioadhesive polymers, carbopol and HPMC and freeze dried to obtain a unit dosage form. The liposomes, liposomal gels and freeze dried rods were evaluated for various parameters. TEM analysis showed the formation of unilamellar liposomes with a mean diameter ranging from 0.9 μm to 1.2 μm. As the cholesterol content increases from 0.5% to 2%w/w, the entrapment efficiency and vesicle size increased. Carbopol gels exhibited higher viscosity, spreadability, mucoadhesiveness than HPMC gels. The redipsersion of freeze dried forms in SVF was found to be slow and its ex‐vivo retention time was found to be 12 hrs while acyclovir gel retained only for 8.25 hrs. The tablet and gel released 96.93±0.15% acyclovir within 6 hrs and 92.31±0.31% by 8 hrs respectively while freeze dried forms could sustain the release upto 12 hrs. From the stability studies the optimum storage condition was found to be 4‐8°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39804.     

Review of crosslinked and non‐crosslinked copolyesters for tissue engineering and drug delivery

Novel degradable biomedical materials are found to have huge potential applications in fields such as drug delivery and release, orthopedic fixation support and tissue engineering. Utilization of polymers as biomaterials has greatly impacted the advancement of modern medicine. In this review, some new degradable biomedical copolyesters reported in recent years are introduced and discussed in combination with some of our research results, including non‐crosslinked copolyesters, crosslinked copolyesters and their corresponding derivatives. The molecular design, chemical structures and related properties of these biodegradable copolyesters are reported. In summarizing the review, the development, potential applications and future directions of degradable biomedical copolyesters are discussed. © 2013 Society of Chemical Industry     

Design and in vitro investigation of nanocomposite hydrogel based in situ spray dressing for chronic wounds and synthesis of silver nanoparticles using green chemistry

An innovative concept of spontaneous film dressing has been designed as sprayed hydrogel dressings (SHD) using a blend of polyvinyl alcohol (PVA) and sodium alginate (SA) as synthetic and natural polymeric components and, were crosslinked with boric acid and calcium chloride, respectively. Silver nanoparticles (AgNPs) are synthesized by green chemistry using Ficus benghalensis extract (FB) and were characterized by SEM and zeta sizer. FTIR spectra show polymeric interaction with AgNP_s, while SEM images show outer surface of the SHD film. Equilibrium swelling and degradation in aqueous media (distilled water and buffers) are found to be dependent upon PVA/SA ratio. Polymeric combination exhibit pseudoplastic behavior with Farrow's constant >1. Uniformly distributed AgNPs (particle size ～27.55 ± 2.01 nm), high water retention (～13 fold), and biodegradable (～5 days) nature of dressing along with sustained release profile of both AgNPs and extract with concentration‐dependent antimicrobial activity have been observed for 24 h. Self shaped, biodegradable, aseptic, prolong anti‐oxidative, non‐hemolytic, blood compatible, and hemostatic properties of SHD film appears as promising dressing for superficial wounds. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43260.     

Development of dual‐triggered in situ gelling scaffolds for tissue engineering

Hydrogel‐forming materials that mimic the three‐dimensional architecture and properties of tissue are known to have a positive effect on cellular differentiation and growth. A subset of those are in situ gels, which utilise in vivo conditions like pH (e.g. acetate phthalate), temperature (e.g. poloxamer) and ionic concentration (e.g. Gelrite?), and can be used to facilitate the delivery of cells to an affected tissue. Hence, we have developed in situ hydrogels based on gellan and hydroxypropylmethylcellulose (HPMC), which are known to be triggered through ions and temperature, respectively, as matrices to deliver cells. Gellan/HPMC blends had a lower gelation temperature than gellan alone crosslinked with calcium, suggesting the role of the dual trigger. Average storage modulus at a frequency of 10 Hz for gellan crosslinked with 3 mmol L^?1 calcium was 4.53 × 10³ Pa; for 9:1 gellan/HPMC crosslinked with 3 mmol L^?1 calcium was 5.59 × 10³ Pa; and for 8:2 gellan/HPMC crosslinked with 3 mmol L^?1 calcium was 2.13 × 10³ Pa, suggesting tunable stiffness by changing the gellan‐to‐HPMC ratio. Hydrophilicity was confirmed using goniometry with a contact angle much less than 90°, facilitating the passage of cells and electrolytes when using the gels as scaffolds. The gels were also found to be porous and non‐toxic to fibroblast cell line L929 and osteosarcoma cell line MG‐63, which, when encapsulated within the gels, were able to grow and proliferate. These blended hydrogels are suitable as scaffolds to encapsulate cells, with tunable stiffness modulated by varying the concentration of gellan and HPMC. © 2014 Society of Chemical Industry     

Self‐assembling chitosan hydrogel: A drug‐delivery device enabling the sustained release of proteins

The development of a self‐assembling hydrogel, prepared from maleimide‐modified and thiolated chitosan (CS), is described. Under mild reaction conditions, the natural CS polymer was coupled with either maleimide or sulfhydryl moieties in a one‐step synthesis. Subsequently, these CS polymers spontaneously formed a covalently crosslinked CS hydrogel when mixed. The three‐dimensional network structure was visualized with scanning electron microscopy. The swelling and degradation behavior was evaluated, and viscosity measurements were conducted. The gel was loaded with the model protein albumin, and prolonged release was achieved. These properties were preserved after lyophilization and rehydration. This makes the hydrogel a promising scaffold for biological wound dressings for the treatment of chronic wounds. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45638.     

Dual stimuli responsive glycidyl methacrylate chitosan‐quaternary ammonium hybrid hydrogel and its bovine serum albumin release

A new family of cationic hybrid hydrogels from two new positively charged aqueous soluble precursors, glycidyl methacrylate‐chitosan (GMA‐chitosan), and 2‐(acryloyloxy) ethyl trimethylammonium (AETA), was developed via a simple photocrosslinking fabrication method. These hybrid hydrogels have pendant quaternary ammonium functional groups on the AETA segments. The chemical composition of GMA‐chitosan/AETA hybrid hydrogels were characterized by Fourier transform infrared spectroscopy and their mechanical, swelling, and morphological properties were examined as a function of the composition of the hybrids as well as the effect of pH and ionic strength of the surrounding medium. GMA‐chitosan/AETA hybrid hydrogels show a porous network structure with average pore diameter 20–50 μm. The compression moduli of these hybrid hydrogels ranged from 27.24 to 28.94 kPa, which are significantly higher than a pure GMA‐chitosan (17.64 kPa). GMA‐chitosan/AETA hybrid hydrogel shows pH/ionic strength responsive swelling behavior because of the presence of the positive charge pendant groups. These hybrid hydrogels showed a sustained BSA protein release and a significantly lower initial burst release than a pure GMA‐chitosan hydrogel. The two aqueous soluble precursors and the cationic charge characteristics of the resulting GMA‐chitosan/AETA hybrid hydrogels may suggest that this new family of biomaterials may have promising applications as the pH responsive protein drug delivery vehicles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3736–3745, 2013     

p(AAm/TA)‐based IPN hydrogel films with antimicrobial and antioxidant properties for biomedical applications

Interpenetrating polymer networks (IPN), either semi‐IPN (s‐IPN) or full IPN, based on a natural polymer tannic acid (TA) and synthetic poly(acrylamide) (p(AAm)) were prepared by incorporation of TA during p(AAm) hydrogel film preparation with and without crosslinking of TA simultaneously. The synthesis of p(AAm/TA) s‐IPN and IPN hydrogels with different amounts of TA were prepared by concurrent use of redox polymerization and epoxy crosslinking. The p(AAm)‐based hydrogels were completely degraded at 37.5°C within 9 and 2 days at pHs 7.4 and 9, respectively. Biocompatibility of p(AAm), s‐IPN, and IPN were tested with WST assay and double staining, they had 75% cell viability up to almost 20 μg mL^?1 concentration against L929 fibroblast cell. Antioxidant properties of IPN and s‐IPN hydrogels were investigated with FC and ABTS^? methods. Antimicrobial properties of TA‐containing s‐IPN, and IPN hydrogels were determined against three common bacterial strains, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 6538, and Bacillus subtilis ATCC 6633, and it was found that p(AAm/TA)‐based s‐IPN and IPN hydrogels are effective antimicrobial and antioxidant materials. Moreover, almost up to day‐long linear TA release profiles were obtained from IPN and s‐IPN hydrogels in phosphate buffer solution at pH 7.4 at 37.5°C. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41876.     

Poly‐3‐hydroxyalkanoates‐co‐polyethylene glycol methacrylate copolymers for pH responsive and shape memory hydrogel

Multifunctional hydrogels combining the capabilities of cellular pH responsiveness and shape memory, are highly promising for the realization of smart membrane filters, controlled drug released devices, and functional tissue‐engineering scaffolds. In this study, lipase was used to catalyze the synthesis of medium‐chain‐length poly‐3‐hydroxyalkanoates‐co‐polyethylene glycol methacrylate (PHA‐PEGMA) macromer, which was used to prepare pH‐responsive and shape memory hydrogel via free radical polymerization. Increasing the PEGMA fraction from 10 to 50% (mass) resulted in increased thermal degradation temperature (T_d) from 430 to 470°C. Highest lower critical solution temperature of 37°C was obtained in hydrogel with 50% PEGMA fraction. The change in PEGMA fraction was also found to highly influence the hydrogel's hydration rate (r) from 2.8 × 10^?5 to 7.6 × 10^?5 mL·s^?1. The hydrogel's equilibrium weight swelling ratio (q_e), protein release and its diffusion coefficient (D_m) were all found to be pH dependent. Increasing the phosphate buffer pH from 2.4 to 13 resulted in increased q_e from 2 to 16 corresponding to the enlarging of network pore size (ξ) from 150 to 586 nm. Different types of crosslinker for the hydrogel influenced its flexibility and ductility. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41149.     

Dual release kinetics of antimalarials from soy protein isolate‐carbopol‐polyacrylamide based hydrogels

The currently used antimalarials suffer from drug resistance which is hampering the global management of malaria infection. To overcome drug resistance, they are administered as combination therapies which involve combination of two or more antimalarials. In this study, chloroquine diphosphate and curcumin were encapsulated onto prepared soy protein isolate‐carbopol‐polyacrylamide based hydrogels. The hydrogels were pH sensitive and exhibited enhanced swelling capability at pH 7.4. The hydrogels were biodegradable which was observed by their SEM images after drug release. The release mechanisms of both drugs were influenced by the degree of crosslinking of the soy protein isolate in the hydrogel network and the presence of the other drug in the network. The release mechanisms of both drugs from the hydrogel networks followed super case transport II. These results suggested that the hydrogels were potential dual drug delivery systems for antimalarials whereby both drugs could work over different period of time and hence, have the potential to overcome drug resistance that is common with the presently used antimalarials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43918.     

Polypropylene oxide/polyethylene oxide-cellulose hybrid nanocomposite hydrogels as drug delivery vehicle

This article deals with the synthesis of hybrid nanocomposite hydrogels through the combination of cellulose (C), polypropylene oxide/poly ethylene oxide (PPO/PEO), and silver nanoparticles (AgNPs) by in situ polymerization technique for the in vitro release of ornidazole drugs. The structure of the resulted materials is identified using SEM, XRD, FTIR, XPS, and TGA spectroscopic techniques. The resulting structure, morphology, thermo responsive property, water retention, and swelling behavior of hydrogels are investigated. The rheological measurement is studied to establish the enhancement of the viscoelasticity and stiffness of hydrogels. The antibacterial activity of the biodegradable silver hybrid nanocomposite hydrogel is investigated by inhibition zone method against gram positive and negative bacteria. Maximum drug release of 96.4% is recorded at 7.4 pH in 5 h. The biocompatibility and cytotoxicity of the hybrid nanocomposite hydrogel are verified using mouse fibroblast cell line L-929 (ATCC CCL-1) cells for their possible use as controlled drug delivery vehicles. The nontoxic nature makes the materials more biocompatible and suitable to apply in the biological systems. Therefore, nontoxic and biocompatible natures of present materials with improved thermal and rheological properties support for their possible uses as drug delivery vehicles.