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Levan-based bioactive hydrogels containing herbal liposome in treating acute wounds

Hydrogels in active wound care products are 3D polymeric scaffolds that provide the desired moisture balance in the wound area with their high water retention capacity. Thanks to their biocompatible properties, flexible and porous structures, and high hydrophilic properties, they have frequently been preferred in the repair and regeneration of cells and tissues and the controlled release of bioactive substances to the target area. In this study, hydrogel structures were developed for the first time with levan produced by Halomonas elongata 153B halophilic bacteria. Extracts from Plantago lanceolata L., commonly known as a wound herb, which has medicinal importance for cell regeneration, ensuring tissue integrity in a short time and reducing infections in the wound area, were obtained and extract-loaded liposome structures were formed for controlled release into the wound area. The wound healing efficacy of the composite material developed by loading herbal liposomes into levan-based hydrogel structures was evaluated in an in vitro wound model. Thus, a natural, biocompatible, biodegradable, and functional wound care product containing herbal liposomes suitable for both clinical applications and point-of-care use has been developed. The developed bioactive hydrogels are a promising therapeutic approach for the healing of acute wounds. Graphical abstract [Formula: see text]

Evaluation of the therapeutic effect of chitosan scaffolds loaded with the different concentrations of Hesperidin in bone regeneration in rat model

Bone grafts are widely used to improve bone healing but this method is costly and make some serious problems like infection in long-term use. To solve these problems, tissue engineering by using scaffolds made of different materials can be used as a supportive structure to enhance bone healing. In the current study, 3-D chitosan (CS) bone scaffold was developed by freeze-drying techniques for bone tissue engineering. The efficiency of the CS scaffold was improved by loading different concentrations of Hesperidin (Hes). Scaffolds were characterized by different mechanical and biological tests to evaluate their properties. In addition, the effect of scaffolds on bone healing was evaluated by a rat femur defect model. Results showed that the porosity of scaffolds was about 45–257 µm and Hes has a negative effect on the mechanical strength of scaffolds. Also, due to the hydrophilic properties of Hes, the degradation rate increased. Histological and CT-Scan evaluation showed that the treated groups which scaffold loaded with 1% and 10% of Hes were fully replaced by new bone and collagenous matrix compared to control and Hesperidin (0%, 0.01%, 0.1%) treated groups. The Runx2 gene expression was significantly increased by 1% and 10% compared to other groups. These results showed the positive effect of the fabricated scaffold on osteogenesis and bone healing and the possibility of using it in clinical trials.

Vancomycin coupled chitosan/PEO nanofibrous scaffold with the desired antibacterial activity as a potential for biomedical application

This study aims to evaluate the Vancomycin (VCM) combination with Chitosan (CS)/ Polyethylene oxide (PEO) nanofibers’ intrinsic antibacterial properties causing a synergistic effect against possible serious bacterial infections (PSBI). VCM/CS nanofiber scaffold was fabricated using the electrospinning method. Characterizations are performed by Fourier transform infrared (FT-IR) to examine the functional groups of each compound, scanning electron microscopy (SEM), and transient electron microscopy (TEM) to evaluate nanofiber diameter and structure. Antibacterial activities of the nanofibrous scaffold were assessed against bacterial strains, including standard Staphylococcus aureus ( S. aureus), VCM-sensitive Enterococcus (VSE), methicillin-resistant S. aureus (MRSA), VCM-resistant Enterococcus (VRE), and Streptococcus group A by microdilution broth methods. The FT-IR, SEM, and TEM examination results confirm the CS/PEO nanofiber scaffold fabrication. The antibacterial examination results showed no significant difference between the minimum inhibitory concentration (MIC) values of VCM and with MIC of VCM/CS nanofibers. Still, there were significant differences between the MIC of CS and VCM/CS nanofibers in S. aureus, but this is not more significant than VCM. This study illustrated that VCM coupled to CS nanofibers had acceptable antibacterial activity against the Gram-positive bacterium. This work motivated researchers’ insight into nanostructures’ potential accompanied by antibacterial polymer and antibiotics synergistic effects against PSBI.

Biomineralization of carboxymethyl cellulose-sodium alginate infused with cellulose nanocrystals for bone regeneration

The development of novel tissue constructs from both natural and synthetic biopolymers has attracted widespread attention among researchers, prior to its excellent outcomes in bone tissue regeneration. This research aims to investigate the biocompatibility of carboxymethyl cellulose (CMC)/sodium alginate (SA) embedded with cellulose nanocrystals (CNC) and its surface response due to the biomineralization process as potential implant material. The CMC/SA were prepared with and without CNC using water as the only solvent. It was then freeze-dried for up to 72 h before being further immersed in simulated body fluid (SBF) for comparative studies. Morphological observation by scanning electron microscope (SEM) showed that CMC/SA/CNC (SBF) displayed a spherical apatite structure amid interconnected porous materials with an average particle diameter between 95 and 148 nm. The apatite crystal indicated the existence of calcium (Ca) and phosphorus (P) elements, which was confirmed by energy dispersive X-ray analysis (EDX). All scaffolds showed a porosity of up to 90.13% with a moderate degradation rate and a water absorption value of up to 1100%. Overall, all scaffolds had open, interconnected pore sizes ranging from 40 to 400 µm. Attenuated total reflection – Fourier Transform Infrared (ATR-FTIR) spectroscopy and thermogravimetric analysis (TGA) curve showed a new existing peak and lower decomposition rate, respectively, for SBF-treated scaffolds. Stress-strain curve disclosed the highest tensile stress of CMC/SA/CNC (SBF) at 16.2 MPa and 15.75% strain effect. Preliminary in vitro cytotoxicity studies performed with human foetal osteoblast (hFOB) cells showed that cytocompatibility was more evident on CMC/SA/CNC (SBF) scaffolds. This study showed that scaffold-embedded CNC with SBF treatment could be hit upon as material selection for bone tissue engineering.

Preparation and evaluation of chitosan-alginate/carrageenan hydrogel for oral drug delivery in the treatment of diabetes

Marine beds are an untapped resource of bioactive materials which can be explored for drug delivery applications. In the present study, a hydrogel was developed with an optimal concentration of sodium alginate-chitosan core polyelectrolytic complex loaded with anti-diabetic drug metformin and coated with ĸ-Carrageenan as an efficient oral drug delivery vehicle. The formulation was optimized by changing parameters such as concentration of polymers, amount of cross-linker and the type and amount of coating material. The prepared hydrogels were characterized for their structural integrity using instrumental techniques such as FTIR, XRD, DSC, and SEM while the physical properties were assessed by evaluating its thickness, UV barrier ability and swelling degree. In vitro study demonstrated the influence of presence and type of coating material affecting drug delivery process. The study suggested that coating with 3% ĸ-Carrageenan (A19) was found most suitable for oral drug delivery since it could resist diffusion of drug in the stomach (pH 1.2) so that maximum drug could reach the intestine (pH 7.4) for absorption. Metformin loaded hydrogel (A20) released ~49% drug in the simulated gastric fluid (pH 1.2). In the simulated intestinal fluid (pH 7.4) both the hydrogel exhibited a sustained release pattern lasting for more than 4 h. Investigation of drug release kinetics using different mathematical models showed that Higuchi model was the best fit release model with R2 ⩾ 0.973. The results indicated that the prepared hydrogels could be potential drug delivery vehicle toward intestine as well as for extended release to colon targeted drug delivery.