Interpenetrating polymeric network hydrogels for potential gastrointestinal drug release

Hydrogels: An overview of its classifications, properties, and applications

The review paper starts with the introduction to hydrogels along with broad literature survey covering different modes of synthesis including high energy radiation methods. After that, paper covered broad classification of the hydrogels depending upon the basis of their source of origin, method of synthesis, type of cross-linking present and ionic charges on bound groups. Another advanced category response triggered hydrogels, which includes pH, temperature, electro, and light and substrate responsive hydrogels was also studied. Presented paper summarises chemical structure, properties, and synthesis of different kinds of hydrogels. Main focus was given to the preparation super absorbents such as: Semi-interpenetrating networks (semi-IPNs), Interpenetrating networks (IPNs) and cross-linked binary graft copolymers (BGCPs). The weak mechanical properties and easy degradation limit the uses of bio-based -hydrogels in biomedical field. Their properties can be improved through different chemical and physical methods. These methods were also discussed in the current research paper. Also, it includes development of hydrogels as controlled drug delivery devices, as implants and biomaterials to replace malfunctioned body parts along with their use in several other applications listed in the literature. Literature survey on the application of hydrogels in different fields like biomedical, nano-biotechnology, tissue engineering, drug delivery and agriculture was also carried out.

Weaving the next generation of (bio)materials: Semi-interpenetrated and interpenetrated polymeric networks for biomedical applications

Advances in polymer science have led to the development of semi-interpenetrated and interpenetrated networks (SIPN/IPN). The interpenetration procedure allows enhancing several important properties of a polymeric material, including mechanical properties, swelling capability, stimulus-sensitive response, and biological performance, among others. More interestingly, the interpenetration (or semi-interpenetration) can be achieved independent of the material size, that is at the macroscopic, microscopic, or nanometric scale. SIPN/IPN have been used for a wide range of applications, especially in the biomedical field, including tissue engineering, delivery of chemical compounds or biological macromolecules, and multifunctional systems as theragnostic platforms. In the last years, this fascinating field has gained a great interest in the area of polymers for therapeutics; therefore, a comprehensive revision of the topic is timely. In this review, we describe in detail the most relevant synthetic approaches to fabricate polymeric IPN and SIPN, ranging from nanoscale to macroscale. The advantages of typical synthetic methods are analyzed, as well as novel and promising trends in the field of advanced material fabrication. Furthermore, the characterization techniques employed for these materials are summarized from physicochemical, thermal, mechanical, and biological perspectives. The applications of novel (semi-)interpenetrated structures are discussed with a focus on drug delivery, tissue engineering, and regenerative medicine, as well as combinations thereof.

In Vitro and Biological Characterization of Dexamethasone Sodium Phosphate Laden pH-Sensitive and Mucoadhesive Hydroxy Propyl β-Cyclodextrin-g-poly(acrylic acid)/Gelatin Semi-Interpenetrating Networks

The current study reports the fabrication and biological evaluation of hydroxy propyl β-cyclodextrin-g-poly(acrylic acid)/gelatin (HP-β-CD-g-poly(AA)/gelatin) semi-interpenetrating networks (semi-IPN) for colonic delivery of dexamethasone sodium phosphate (DSP). The prepared hydrogels showed pH-dependent swelling and mucoadhesive properties. The mucoadhesive strength of hydrogels increased with an increasing concentration of gelatin. Based on the swelling and mucoadhesive properties, AG-1 was chosen as the optimized formulation (0.33% w/w of gelatin and 16.66% w/w of AA) for further analysis. FTIR revealed the successful development of a polymeric network without any interaction with DSP. SEM images revealed a slightly rough surface after drug loading. Drug distribution at the molecular level was confirmed by XRD. In vitro drug release assay showed pH-dependent release, i.e., a minute amount of DSP was released at a pH of 1.2 while 90.58% was released over 72 h at pH 7.4. The optimized formulation did not show any toxic effects on a rabbit's vital organs and was also hemocompatible, thus confirming the biocompatible nature of the hydrogel. Conclusively, the prepared semi-IPN hydrogel possessed the necessary features, which can be exploited for the colonic delivery of DSP.

Novel fabrication of dual nanoparticle loaded-co-polymeric dressing for effective healing efficiency in wound care after fracture surgery

In the present study, curcumin loaded chitosan/poly ethylene glycol nanomaterial (CUR loaded CH/PEG/AgNPs) was fabricated and characterized for wound healing efficiency after fracture surgery. The interaction of functional groups and crystal nature were recorded under FTIR and XRD spectrometer and reveals that the stabilization and purity of NPs was mediated by OH/NH₂ groups in chitosan. FESEM showed the presence of spherical and well dispersed particles. The average size of the particle was 13.48 nm. The CUR loaded CH/PEG/AgNPs showed higher swelling capacity (495.6 g/g) in phosphate buffer saline compared to water (140.2 g/g). The drug loading efficiency was higher in CUR loaded CH/PEG/AgNPs compared to CH/PEG films as recorded by the absorbance peak at 460 nm corresponds to curcumin in the composite. A dose dependent cytotoxicity of CUR loaded CH/PEG/AgNPs was noticed on Vero cells. The viability of Vero cells was increased to 96.5% at 100 μg/mL. A remarkable change in Vero cells such as condensed nuclei and membrane blabbing was noticed in cells treated with CUR loaded CH/PEG/AgNPs. A greater inhibition of Staphylococcus aureus and Escherichia coli was noticed at 24 h and 48 h treated with CUR loaded CH/PEG/AgNPs. A greater healing effect by increasing the wound contraction (98% on day 12) was observed with CUR loaded CH/PEG/AgNPs compared to control. Histopathological examination demonstrated that CUR loaded CH/PEG/AgNPs showed complete tissue regeneration in wound excised rats. The results of this study conclude that CUR loaded CH/PEG/AgNPs could be promising candidate to prevent microbial infections in wound, healing wound rapidly and inhibit the proliferation of apoptotic cells. Thus, CUR loaded CH/PEG/AgNPs could be a potential therapeutic agent with broad spectrum applications in the future. HighlightsA new approach was used to develop curcumin-loaded chitosan/poly(ethylene glycol)/AgNPs.The CUR-loaded CH/PEG/AgNPs were confirmed to be crystals by XRD analysis.The prepared CH/PEG/AgNPs were spherical and averaged 13.48 nm in size.The growth of S. aureus and E. coli were inhibited mostly by CH/PEG/AgNPs treatment.CUR loaded CH/PEG/AgNPs showed complete tissue regeneration in wound excised mice.

In vitro study of chitosan-based multi-responsive hydrogels as drug release vehicles: a preclinical study

Systematic administration of painkillers and anti-inflammatory drugs is routinely employed to minimize pain and bodily disorders. Controlled drug delivery has the potential to improve the outcomes of disorders by providing sustained exposure to efficacious drug concentrations. Herein, we report the fabrication of multi-responsive hydrogels using reactive and functional polymers such as chitosan and polyvinyl pyrrolidone by varying the concentration of a cleavable crosslinker, tetraethyl orthosilicate. The swelling indices of the hydrogels were evaluated in distilled water, solutions with different pH values and different electrolytes. FTIR, WAXRD and TGA were conducted to investigate the structures, crystallinities and thermal stabilities of the prepared multi-responsive hydrogels, respectively. The ultimate tensile strength and elongations at break of the fabricated hydrogels were investigated to assess their mechanical stability. Optical microscopy, biodegradation, antimicrobial and cytotoxicity analyses were further carried out to verify the magnified crosslinked and porous structures, biodegradabilities, biocompatibilities and toxic behaviour of the as-prepared hydrogels, respectively. Drug release analysis was conducted to evaluate their release behaviour in PBS, SGF, SIF and electrolyte solutions. The overall results indicate the successful development of novel, non-toxic and sustained drug deliverable hydrogels, which can be considered as a paramount success towards the fabrication of controlled drug delivery systems.

Stomach-Specific Drug Delivery of Clarithromycin Using a Semi Interpenetrating Polymeric Network Hydrogel Made of Montmorillonite and Chitosan: Synthesis, Characterization and In Vitro Drug Release Study

Purpose: In this study, we aimed to prepare an extended drug delivery formulation of clarithromycin (CAM) based on a semi-interpenetrating polymer network (semi-IPN) hydrogel. Methods: Synthesis of semi-IPN hydrogel nanocomposite made of chitosan (CS), acrylic acid (AA), acrylamide (AAm), polyvinylpyrrolidone (PVP), and montmorillonite (MMT) was performed by free radical graft copolymerization method. Swelling kinetic studies were done in acidic buffer solutions of hydrochloric acid (pH = 1.2), acetate (pH = 4), and also distilled water. Also, the effects of MMT on the swelling kinetic, thermal stability, and mechanical strength of the hydrogels were evaluated. Moreover, in vitro release behavior of CAM and its release kinetics from hydrogels were studied in a hydrochloric acid buffer solution. Results: Fourier transform infrared spectroscopy (FTIR) results revealed that synthesis of semi- IPN superabsorbent nanocomposite and CAM incorporation into hydrogel was performed, successfully. Introducing MMT into hydrogel network not only improved its thermal stability but also increased mechanical strength of the final hydrogel product. Also, in comparison with neat hydrogel (1270 g/g), hydrogel nanocomposite containing 13 wt% MMT exhibited greater equilibrium swelling capacity (1568 g/g) with lower swelling rate. In vitro drug release experiments showed that CS-g-poly(AA-co-AAm)/PVP/MMT/CAM formulation possesses a sustained release character over extended period of time compared with CS-g-poly(AA-co- AAm)/PVP/CAM formulation. Conclusion: In the presence of MMT, the effective life time of drug is prolonged, demonstrating a sustained release property. The reason is that interlinked porous channels within superabsorbent nanocomposite network hinder penetration of aqueous solutions into hydrogel and subsequently cause a slower drug release.

Evaluation of a conducting interpenetrating network based on gum ghatti-g-poly(acrylic acid-aniline) as a colon-specific delivery system for amoxicillin trihydrate and paracetamol

Development of colon-specific drug delivery systems for amoxicillin trihydrate and paracetamol using gum ghatti based crosslinked hydrogels.

Characterization and evaluation of curcumin loaded guar gum/polyhydroxyalkanoates blend films for wound healing applications

Schematic representation of the blockage of UV rays and controlled release of curcumin on a wound.

Optimal response surface design of Gum tragacanth-based poly[(acrylic acid)-co-acrylamide] IPN hydrogel for the controlled release of the antihypertensive drug losartan potassium

The present study proposes the development and optimization of a new interpenetrating polymer network (IPN), consisting of Gum tragacanth, poly(acrylic acid) (PAA), and poly(acrylamide) (PAAm), for the in situ controlled release of losartan potassium under different pH conditions at 37 °C.

Fabrication of silver nanocomposite films impregnated with curcumin for superior antibacterial applications

Silver nanocomposite films are found to be very effective material for anti-bacterial application. In the present work, sodium carboxylmethyl cellulose silver nanocomposite films (SCMC SNCF) were tried for antibacterial applications. To enhance their applicability novel film-silver nanoparticle-curcumin composites have been developed. SCMC SNCF are developed from sodium carboxylmethyl cellulose (SCMC), N,N(1)-methylenebisacrylamide (MBA) and silver nitrate solution. These films were characterized by FTIR, UV-visible, XRD, TGA, DSC and TEM techniques. The formed silver nanoparticles have an average particle size of ~15 nm as observed by transmission electron microscopy (TEM). Curcumin loading into SCMC SNCF is achieved by diffusion mechanism. The UV-Visible analysis indicated that higher encapsulation of curcumin in the films with higher SCMC content. Further, it was observed that the presence of silver nanoparticles in the films enhanced the encapsulation of curcumin indicating an interaction between them. Moreover, the antibacterial activity showed that the SCMC films generated with silver nanoparticles have a synergistic effect in the antimicrobial activity against Escherichia coli (E. coli). In order improve the healing efficacy as antibacterial agents, curcumin loaded with SCMC SNCFs were developed which showed significant inhibition of E. coli growth than the silver nanoparticles and curcumin alone film. Therefore, the present study clearly provides novel antimicrobial films which are potentially useful in preventing/treating infections.