Semi-interpenetrating hydrogels from carboxymethyl guar gum and gelatin for ciprofloxacin sustained release

Synthesis and characterization of novel carboxymethyl tamarind kernel gum - Poly (vinyl alcohol)/guar gum-based hydrogel film loaded with ciprofloxacin for biomedical applications

The current study delineates the synthesis of hydrogel films comprised of carboxymethyl tamarind kernel gum (CMTKG), poly (vinyl alcohol) (PVA), and guar gum (GG) using glutaraldehyde (GTA) as cross-linker. The hydrogel films were evaluated in terms of equilibrium swelling ratio (ESR), moisture content, thickness, wetting analysis, thermal, and mechanical analysis. The tensile strength value lies in the range of 95.80 to 149.07 MPa while elongation at break value lies in the range of 1.51 to 5.20 %. The FTIR spectroscopy confirmed the presence of hydrogen bonding between CMTKG, PVA, and GG components of hydrogel film. FE-SEM micrographs indicated the rough surfaces of hydrogel film. TGA-DTA analysis confirmed that the thermal stability of hydrogel film was found to be increased by incorporating the ciprofloxacin (CFX) drug into the hydrogel matrix. CFX was embedded in the best-swelled hydrogel film and in-vitro drug release behavior was studied at alkaline pH 7.4 phosphate buffer solution. It was found that the maximum drug release was to be 73 % after 24 h at pH 7.4. Moreover, the release data was fitted in various kinetic models such as the First-order, Higuchi, and Korsmeyer-Peppas models. The best-fitted Korsmeyer-Peppas model suggested that the release of the drug follows Fickian diffusion and the value of diffusion exponent (n) was determined to be 0.38. The cytocompatibility of the hydrogel film was analyzed by MTT assay while the antibacterial behavior of the hydrogel film against E. coli and S. aureus showed clear zone of inhibition area. Thus, the overall results indicated that CMTKG/PVA/GG hydrogel film have potential to be used in the biomedical applications.

Chitosan/Fibroin Biopolymer-Based Hydrogels for Potential Angiogenesis in Developing Chicks and Accelerated Wound Healing in Mice

Potential therapies for wound management remain one of the most challenging affairs to date. Biopolymer hydrogels possess inherent properties that facilitate the healing of damaged tissue by creating a supportive and hydrated environment. Chitosan/fibroin hydrogels were formulated with poly (vinyl pyrrolidone) and cross-linked using 3-aminopropyl (diethoxy) methylsilane (APDEMS) for the aforementioned function. The hydrogels were characterized through Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy, and their swelling response was observed using a variety of solvents. Additionally, hydrogels were investigated for biomedical applications. As the amount of fibroin added to the hydrogels increased, the swelling ratio decreased. The analysis of chorioallantoic membrane (CAM) assay revealed that higher concentrations of fibroin in the hydrogel were directly correlated with increased angiogenesis. The intragroup comparison showed that the vascular number in the CPF5 group was significantly increased (p ≤ 0.05) compared to other hydrogel groups. The wound healing efficiency of the prepared hydrogels showed that the rate of wound reduction (99.06%) was remarkably (p ≤ 0.05) high in the hydrogel group with a greater fibroin content against control (67.03%). Histological findings of wounded tissues corroborate the abovementioned results, showing dense fibrous connective tissues in the fibroin group compared to the control. The results of this work provide thorough preclinical evidence that chitosan-fibroin biopolymers are involved in enhanced angiogenesis in growing chicks and speed up wound healing in mice without any obvious toxicity.

Recent updates on guar gum derivatives in colon specific drug delivery

Colon specific delivery of therapeutics have gained much attention of pharmaceutical researchers in the recent past. Colonic specific targeting of drugs is used not only for facilitating absorption of protein or peptide drugs, but also localization of therapeutic agents in colon to treat several colonic disorders. Among various biopolymers, guar gum (GG) exhibits pH dependent swelling, which allows colon specific release of drug. GG also shows microbial degradation in the colonic environment which makes it a suitable excipient for developing colon specific drug delivery systems. The uncontrolled swelling and hydration of GG can be controlled by structural modification or by grafting with another polymeric moiety. Several graft copolymerized guar gum derivatives are investigated for colon targeting of drugs. The efficacy of various guar gum derivatives are evaluated for colon specific delivery of drugs. The reviewed literature evidenced the potentiality of guar gum in localizing drugs in the colonic environment. This review focuses on the synthesis of several guar gum derivatives and their application in developing various colon specific drug delivery systems including matrix tablets, coated formulations, nano or microparticulate delivery systems and hydrogels.

Advances in enhancing the mechanical properties of biopolymer hydrogels via multi-strategic approaches

The limited mechanical properties of biopolymer-based hydrogels have hindered their widespread applications in biomedicine and tissue engineering. In recent years, researchers have shown significant interest in developing novel approaches to enhance the mechanical performance of hydrogels. This review focuses on key strategies for enhancing mechanical properties of hydrogels, including dual-crosslinking, double networks, and nanocomposite hydrogels, with a comprehensive analysis of their underlying mechanisms, benefits, and limitations. It also introduces the classic application scenarios of biopolymer-based hydrogels and the direction of future research efforts, including wound dressings and tissue engineering based on 3D bioprinting. This review is expected to deepen the understanding of the structure-mechanical performance-function relationship of hydrogels and guide the further study of their biomedical applications.

Applications of guar gum polysaccharide for pharmaceutical drug delivery: A review

Bio-based materials are rapidly replacing synthetic materials owing to their significant biomedical applications, easy availability, nontoxicity, biodegradability and biocompatibility. Guar gum (GG) is a plant-derived biocompatible and biodegradable polymeric compound found abundantly in nature. It is a non-ionic, hydrophilic carbohydrate and is a cost-effective hydrocolloid polysaccharide considered as a wonderful representative of the new generation of plant gums. Various composites of guar gum with other polymers have been reported in last few decades and they are extensively used in different industries like food, textile, mining, petrochemical, paper and explosives etc. Easy availability, non-toxicity, eco-friendly and biodegradable nature of GG has made it ideal candidate for for drug delivery (DD) applications. GG based hydrogels, films, scaffolds and nanoparticles have been explored widely for their DD applications. These non-toxic DD carriers can be used for targeted drug delivery. This review article directs the current efforts and improvements on GG and GG-based materials to be used in DD.

Effects of Transglutaminase Concentration and Drying Method on Encapsulation of Lactobacillus plantarum in Gelatin-Based Hydrogel

Lactobacillus plantarum is a kind of probiotic that benefits the host by regulating the gut microbiota, but it is easily damaged when passing through the gastrointestinal tract, hindering its ability to reach the destination and reducing its utilization value. Encapsulation is a promising strategy for solving this problem. In this study, transglutaminase (TGase)-crosslinked gelatin (GE)/sodium hexametaphosphate (SHMP) hydrogels were used to encapsulate L. plantarum. The effects of TGase concentration and drying method on the physiochemical properties of the hydrogels were determined. The results showed that at a TGase concentration of 9 U/gGE, the hardness, chewiness, energy storage modulus, and apparent viscosity of the hydrogel encapsulation system were maximized. This concentration produced more high-energy isopeptide bonds, strengthening the interactions between molecules, forming a more stable three-dimensional network structure. The survival rate under the simulated gastrointestinal conditions and storage stability of L. plantarum were improved at this concentration. The thermal stability of the encapsulation system dried via microwave vacuum freeze drying (MFD) was slightly higher than that when dried via freeze drying (FD). The gel structure was more stable, and the activity of L. plantarum decreased more slowly during the storage period when dried using MFD. This research provides a theoretical basis for the development of encapsulation technology of probiotics.

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.

Polymer based dual drug delivery system for targeted treatment of fluoroquinolone resistant Staphylococcus aureus mediated infections

The present study attempts to treat S. aureus-induced soft skin infections using a combinatorial therapy with an antibiotic, Ciprofloxacin (CIP), and an efflux pump inhibitor 5-Nitro-2-(3-phenylpropoxy) pyridine (5-NPPP) through a smart hydrogel delivery system. The study aims to reduce the increasing rates of infections and antimicrobial resistance; therefore, an efflux pump inhibitor molecule is synthesized and delivered along with an antibiotic to re-sensitize the pathogen towards antibiotics and treat the infections. CIP-loaded polyvinyl alcohol (PVA) hydrogels at varying concentrations were fabricated and optimized by a chemical cross-linking process, which exhibited sustained drug release for 5 days. The compound 5-NPPP loaded hydrogels provided linear drug release for 2 days, necessitating the need for the development of polymeric nanoparticles to alter the release drug pattern. 5-NPPP loaded Eudragit RSPO nanoparticles were prepared by modified nanoprecipitation-solvent evaporation method, which showed optimum average particle size of 230-280 nm with > 90% drug entrapment efficiency. The 5-NPPP polymeric nanoparticles loaded PVA hydrogels were fabricated to provide a predetermined sustained release of the compound to provide a synergistic effect. The selected 7% PVA hydrogels loaded with the dual drugs were evaluated using Balb/c mice models induced with S. aureus soft skin infections. The results of in vivo studies were evidence that the dual drugs loaded hydrogels were non-toxic and reduced the bacterial load causing re-sensitization towards antibiotics, which could initiate re-epithelization. The research concluded that the PVA hydrogels loaded with CIP and 5-NPPP nanoparticles could be an ideal and promising drug delivery system for treating S. aureus-induced skin infections.

Guar gum-based nanoformulations: Implications for improving drug delivery

Poorly soluble drugs are reported to easily degrade in the gastrointestinal tract and contribute in limiting the effect of drug to its targeted site. Oral administration of drug is one of the prominent ways to deliver a drug, although, it experiences barriers like acidic pH, presence of microflora and enzymes in the gastrointestinal tract. Collectively all of these participate in the degradation of drug before it reaches its target site and thus, they impede the sustained effect of drug. A quest of choosing a polymer with good stability profile and releasing the drug to its targeted site is always been a challenge for the scientists worldwide. Many polymers have been reported to prevent the degradation of drug and one such naturally occurring biocompatible polymer is guar gum. Guar gum-based nanoformulations have been extensively used in past decades to achieve controlled drug release which defines its importance. The coating of guar gum over the drug improves the bioavailability of the drug and thus helps in minimizing the risk of drug degradation. This review intends to highlight the beneficial role of guar gum-based nanoformulations to improve drug delivery by ameliorating the bioavailibility.

Quarternized chitosan/quercetin/polyacrylamide semi-interpenetrating network hydrogel with recoverability, toughness and antibacterial properties for wound healing

Antibiotic abuse has posed enormous burdens on patients and healthcare systems. Hence, the design and development of non-antibiotic wound dressings to meet clinical demand are urgently desired. However, there remains one of the impediments to hydrogel wound dressings that integrated with good recoverability, toughness, and excellent antibacterial properties. Herein, a series of semi-interpenetrating network (semi-IPN) hydrogels with exceptional mechanical performance and remarkable antibacterial activity based on quaternized chitosan (QCS) and polyacrylamide (PAM) were developed using a one-pot method. Additionally, the antibacterial activity of semi-IPN hydrogel against S. aureus and E. coli was enhanced by integrating it with quercetin (QT). The semi-IPN hydrogels also exhibited high recoverability and toughness, outstanding liquid absorbability (the swelling ratio reached 565 ± 12 %), and a satisfying water vapor transmission rate. Moreover, the semi-IPN hydrogels presented ideal hemocompatibility and cytocompatibility. These high-elastic hydrogels are promising candidates for potential applications in wound dressing, tissue repair, chronic wound care, as well as other biomedical fields.

In Vitro and In Vivo Evaluation of Hydroxypropyl-β-cyclodextrin-grafted-poly(acrylic acid)/poly(vinyl pyrrolidone) Semi-Interpenetrating Matrices of Dexamethasone Sodium Phosphate

In this paper, we fabricated semi-interpenetrating polymeric network (semi-IPN) of hydroxypropyl-β-cyclodextrin-grafted-poly(acrylic acid)/poly(vinyl pyrrolidone) (HP-β-CD-g-poly(AA)/PVP) by the free radical polymerization technique, intended for colon specific release of dexamethasone sodium phosphate (DSP). Different proportions of polyvinyl pyrrolidone (PVP), acrylic acid (AA), and hydroxypropyl-beta-cyclodextrin (HP-β-CD) were reacted along with ammonium persulphate (APS) as initiator and methylene-bis-acrylamide (MBA) as crosslinker to develop a hydrogel system with optimum swelling at distal intestinal pH. Initially, all formulations were screened for swelling behavior and AP-8 was chosen as optimum formulation. This formulation was capable of releasing a small amount of drug at acidic pH (1.2), while a maximum amount of drug was released at colonic pH (7.4) by the non-Fickian diffusion mechanism. Fourier transformed infrared spectroscopy (FTIR) revealed successful grafting of components and development of semi-IPN structure without any interaction with DSP. Thermogravimetric analysis (TGA) confirmed the thermal stability of developed semi-IPN. X-ray diffraction (XRD) revealed reduction in crystallinity of DSP upon loading in the hydrogel. The scanning electron microscopic (SEM) images revealed a rough and porous hydrogel surface. The toxicological evaluation of semi-IPN hydrogels confirmed their bio-safety and hemocompatibility. Therefore, the prepared hydrogels were pH sensitive, biocompatible, showed good swelling, mechanical properties, and were efficient in releasing the drug in the colonic environment. Therefore, AP-8 can be deemed as a potential carrier for targeted delivery of DSP to treat inflammatory bowel diseases.

Honey-Loaded Reinforced Film Based on Bacterial Nanocellulose/Gelatin/Guar Gum as an Effective Antibacterial Wound Dressing

Recently, the use of bacterial nanocellulose (BNC) produced by Acetobacter, which has suitable properties for tissue engineering application as a perfect wound dressing, has attracted considerable attention. For this purpose, we successfully developed honey loaded BNC-reinforced gelatin/dialdehyde-modified guar gum films (H/BNC/Ge/D-GG). Prepared films were studied for their morphological, thermal stability, mechanical, water solubility and degradability properties. The physicochemical properties of the developed films with or without honey loading were studied. The results indicated that by enhancing the honey content of the film, the degradation behavior, adhesion and proliferation of NIH-3T3 fibroblast cells were improved. The films with 15 wt% of honey revealed inhibition activity against S. aureus (13.0±0.1 mm) and E. coli (15.0±1.0 mm) bacteria. Cell culture results demonstrated that the prepared films had good cytocompatibility. Based on the results, the prepared H/BNC/Ge/D-GG films appear to have high potential for antibacterial wound dressings.

Preparation, properties, and applications of gelatin-based hydrogels (GHs) in the environmental, technological, and biomedical sectors

Gelatin's versatile functionalization offers prospects of facile and effective crosslinking as well as combining with other materials (e.g., metal nanoparticles, carbonaceous, minerals, and polymeric materials exhibiting desired functional properties) to form hybrid materials of improved thermo-mechanical, physio-chemical and biological characteristics. Gelatin-based hydrogels (GHs) and (nano)composite hydrogels possess unique functional features that make them appropriate for a wide range of environmental, technical, and biomedical applications. The properties of GHs could be balanced by optimizing the hydrogel design. The current review explores the various crosslinking techniques of GHs, their properties, composite types, and ultimately their end-use applications. GH's ability to absorb a large volume of water within the gel network via hydrogen bonding is frequently used for water retention (e.g., agricultural additives), and absorbency towards targeted chemicals from the environment (e.g., as wound dressings for absorbing exudates and in water treatment for absorbing pollutants). GH's controllable porosity makes its way to be used to restrict access to chemicals entrapped within the gel phase (e.g., cell encapsulation), regulate the release of encapsulated cargoes within the GH (e.g., drug delivery, agrochemicals release). GH's soft mechanics closely resembling biological tissues, make its use in tissue engineering to deliver suitable mechanical signals to neighboring cells. This review discussed the GHs as potential materials for the creation of biosensors, drug delivery systems, antimicrobials, modified electrodes, water adsorbents, fertilizers and packaging systems, among many others. The future research outlooks are also highlighted.

Seed gum-based delivery systems and their application in encapsulation of bioactive molecules

Now-a-days, the food/pharma realm faces with great challenges for the application of bioactive molecules when applying them in free form due to their instability in vitro/in vivo. For promoting the biological and functional properties of bioactive molecules, efficient delivery systems have played a pivotal role offering a controlled delivery and improved bioavailability/solubility of bioactives. Among different carbohydrate-based delivery systems, seed gum-based vehicles (SGVs) have shown great promise, facilitating the delivery of a high concentration of bioactive at the site of action, a controlled payload release, and less bioactive loss. SGVs are potent structures to promote the bioavailability, beneficial properties, and in vitro/in vivo stability of bioactive components. Here, we offer a comprehensive overview of seed gum-based nano- and microdevices as delivery systems for bioactive molecules. We have a focus on structural/functional attributes and health-promoting benefits of seed gums, but also strategies involving modification of these biopolymers are included. Diverse SGVs (nano/microparticles, functional films, hydrogels/nanogels, particles for Pickering nanoemulsions, multilayer carriers, emulsions, and complexes/conjugates) are reviewed and important parameters for bioactive delivery are highlighted (e.g. bioactive-loading capacity, control of bioactive release, (bio)stability, and so on). Future challenges for these biopolymer-based carriers have also been discussed. HighlightsSeed gum-based polymers are promising materials to design different bioactive delivery systems.Seed gum-based delivery systems are particles, fibers, complexes, conjugates, hydrogels, etc.Seed gum-based vehicles are potent structures to promote the bioavailability, beneficial properties, and in vitro/in vivo stability of bioactive components.

Structural changes in pH-responsive gelatin/hydroxypropyl methylcellulose phthalate blends aimed at drug-release systems

The present study aimed to investigate the thermal- and pH-dependent gelation behavior of gelatin/HPMCP blends using ultraviolet (UV) spectrophotometry, viscoelasticity, and dynamic light scattering (DLS). We found that the release of lisinopril from gelatin/HPMCP gels can be inhibited at low pH. UV spectrophotometric analysis showed that pH had a significant effect on the transparency of aqueous HPMCP systems and gelatin/HPMCP gels. The viscoelastic patterns of gelatin/HPMCP at pH 4.6 considerably differed from those of gelatin/HPMCP at pH 5.2 and 6.0. DLS measurements showed that HPMCP molecules in low concentrations underwent strong aggregation below pH 4.8. Such HPMCP aggregation induces a physical barrier in the matrix structures of the gelatin/HPMCP gels, which inhibits the drug release at pH 1.2. This hydrogel delivery system using polymer blends of gelatin/HPMCP can be used in oral gel formulations with pH-responsive properties.

Recent advances in guar gum based drug delivery systems and their administrative routes

Guar gum-based drug carrier systems have gained attention for the delivery of various therapeutic agents via different administration routes for attaining controlled and sustained release. Guar gum offers a safe and effective system for drug delivery due to its natural occurrence, easy availability, biocompatibility, and biodegradability, besides simple and mild preparation techniques. Furthermore, the possibility of using various routes such as oral, buccal, transdermal, intravenous, and gene delivery further diversify guar gum applications in the biomedical field. This review delineates the recent investigation on guar gum-based drug carrier systems like hydrogels, nanoparticles, nanocomposites, and scaffolds along with their related delivery routes. Also, the inclusion of data of the loading and subsequent release of the drugs enables to explore the noble and improved drug targeting therapies.

Osteogenic Effect of a Biodegradable BMP-2 Hydrogel Injected into a Cannulated Mg Screw

Cannulated screws, containing an internal hole for inserting a guide pin, are commonly used in the management of bone fractures. Cannulated Mg screws can be biodegraded easily because their increased surface area including that of the inner hole rapidly reacts with body fluids. To delay biodegradation of cannulated Mg screws and improve bone regeneration, we developed a specific type of screw by injecting it with gelatin hydrogels [10 wt % gelatin_(gel) with 0.09 v/v % glutaraldehyde (cross-linker)] containing different concentrations (5, 10, or 25 μg/mL) of bone morphogenic proteins (BMPs). We analyzed the properties and biocompatibility of the screws with and without BMP-2 and found that the release rate of BMP-2 in the hydrogel changed proportionately with the degradation rate of the cross-linked hydrogel. Loading BMP-2 in the hydrogel resulted in sustained release of BMP-2 for 25 to 40 days or more. The degradation rate of BMP-2 hydrogels was inversely proportional to the concentration of BMP-2. The injection of the hydrogels in the cannulated screw delayed biodegradation inside of the screw by simulated body fluid. It also induced uniform corrosion and the precipitation of bioactive compounds onto the surface of the screw. In addition, osteoblast proliferation was very active near the BMP-2 hydrogels, depending on the BMP-2 concentration. The BMP-2 in the hydrogel improved cell differentiation. The cannulated screw injected with 10 μL/mL BMP-2 hydrogel prevented implant biodegradation and enhanced osteoconduction and osteointegration inside and outside the screw. In addition, the properties of BMP-2-loaded hydrogels can be changed by controlling the amount of the cross-linker and protein, which could be useful for tissue regeneration in other fields.

Osteogenic differentiation of hMSCs on semi-interpenetrating polymer networks of polyurethane/poly(2‑hydroxyethyl methacrylate)/cellulose nanowhisker scaffolds

Poly (2‑hydroxyethyl methacrylate) (PHEMA) was crosslinked in the presence of biocompatible and biodegradable poly(caprolactone) (PCL) based polyurethanes (PUs) and cellulose nanowhiskers (CNWs). The CNWs were obtained from wastepaper. In order to crosslink PHEMA (10 wt%), a novel acrylic-urethane cross-linker was produced by a condensation reaction of PHEMA and hexamethylene diisocyanate (HDI). The PU-PHEMA-CNWs scaffolds were prepared by solvent casting/particulate leaching method in different weight percentages of CNWs (i.e., 0, 0.1, 0.5, and 1 wt%). The structural, mechanical, and in vitro biological properties of bio-nanocomposites were evaluated via FTIR, SEM, tensile, and MTT assay. The tensile strength of PU-PHEMA-0, PU-PHEMA-0.1, PU-PHEMA-0.5, and PU-PHEMA-1 were 76.2, 95.8, 98.1, and 89.8 kPa, respectively. Incorporation of CNWs also resulted in improved cell proliferation on PU-PHEMA-CNWs scaffolds. The bone marrow derived human mesenchymal stem cells (hMSCs) were seeded on the prepared porous scaffolds and incubated in osteogenic medium. Based on the results including calcium content assay, alkaline phosphatase assay, and mineralization staining, PU-PHEMA-CNW scaffolds were introduced as a suitable election for imitating the behavior of cellular niche. Bone mineralization and osteogenesis differentiation of hMSCs on PU-PHEMA-CNW scaffolds were significantly more than control after 14 days.