The exopolysaccharide produced by Pantoea sp. BCCS 001 GH provides hepatoprotection in a rat model of bile duct obstruction

Liver injury is a severe clinical complication associated with various diseases or xenobiotics exposure. Hence, finding safe and clinically applicable hepatoprotective agents have great value. Several naturally-derived chemicals have gotten attention for their biological functions. Polysaccharides are bioactive and safe chemicals produced by a variety of microorganisms. Several exciting features, including radical scavenging and antioxidative properties, have been attributed to polysaccharides. Recently we found that the exopolysaccharide derived from Pentoea sp. BCCS 001 GH (Pentoan exopolysaccharide; PEPS) revealed significant antioxidant and radical scavenging properties in an in vitro model. Hence, the current study was designed to evaluate the in vivo hepatoprotective effects of PEPS. Bile duct ligated (BDL) rats received PEPS (0.05 and 0.1% w: v in drinking water), and serum biomarkers of liver injury, liver tissue histopathological alterations, and hepatic markers of oxidative stress were monitored. Severely elevated serum biomarkers of liver injury and histopathological changes, including inflammatory cell infiltration, necrosis, bile duct proliferation, and tissue fibrosis, were evident in BDL animals. Moreover, a significant amount of reactive oxygen species, increased level of lipid peroxidation, and defects in tissue antioxidant capacity were apparent in BDL rats. It was found that PEPS significantly improved liver function, blunted hepatic pathological changes, and counteracted oxidative stress in the liver tissue. The radical scavenging and antioxidant properties of PEPS seem to play a fundamental role in its hepatoprotective properties. Please cite this article as: Seyyed Vahid Niknezhad, Younes Ghasemi, Ali Khalili Gashtroudkhani, Hamidreza Mohammadi, Reza Heidari. The exopolysaccharide produced by Pantoea sp. BCCS 001 GH provides hepatoprotection in a rat model of bile duct obstruction. Trends in Pharmaceutical Sciences. 2022;8(4):211-222. doi: 10.30476/tips.2022.95246.114

Sprayable antibacterial Persian gum-silver nanoparticle dressing for wound healing acceleration

Wound infection is considered a significant challenge in skin injuries. Sprayable antibacterial wound dressings are interesting alternatives to their traditional counterparts because of their facile preparation, ease-of-use, and the possibility of topical delivery of antibacterial materials. Herein, novel sprayable antibacterial dressings are formulated and reported. The dressings were developed by in-situ formation of Ag-nanoparticles (Ag-NPs) using Persian gum (PG) as a carbohydrate polymer. Several tests were conducted to investigate the effect of polymer concentration on the sprayablity, biocompatibility, and antibacterial activity of the dressings (PG/Ag-NPs). Results showed that formulations up to 2 wt.% PG/Ag-NPs could be sprayed properly and form intact films. Antibacterial evaluations also showed biocidal activity of 1% PG/Ag-NPs against Pseudomonas aeruginosa and Staphylococcus aureus. Cytotoxicity and in vivo full-thickness wound healing evaluation confirmed that 1% PG/ Ag-NPs spray was safe and improved wound healing process. All the results confirmed the high potential of formulated sprayable dressings for wound repair.Peer reviewe

Enhancing volumetric muscle loss (VML) recovery in a rat model using super durable hydrogels derived from bacteria

Bacteria can be programmed to deliver natural materials with defined biological and mechanical properties for controlling cell growth and differentiation. Here, we present an elastic, resilient and bioactive polysaccharide derived from the extracellular matrix of Pantoea sp. BCCS 001. Specifically, it was methacrylated to generate a new photo crosslinkable hydrogel that we coined Pantoan Methacrylate or put simply PAMA. We have used it for the first time as a tissue engineering hydrogel to treat VML injuries in rats. The crosslinked PAMA hydrogel was super elastic with a recovery nearing 100 %, while mimicking the mechanical stiffness of native muscle. After inclusion of thiolated gelatin via a Michaelis reaction with acrylate groups on PAMA we could also guide muscle progenitor cells into fused and aligned tubes – something reminiscent of mature muscle cells. These results were complemented by sarcomeric alpha-actinin immunostaining studies. Importantly, the implanted hydrogels exhibited almost 2-fold more muscle formation and 50 % less fibrous tissue formation compared to untreated rat groups. In vivo inflammation and toxicity assays likewise gave rise to positive results confirming the biocompatibility of this new biomaterial system. Overall, our results demonstrate that programmable polysaccharides derived from bacteria can be used to further advance the field of tissue engineering. In greater detail, they could in the foreseeable future be used in practical therapies against VML.</p

Enhancing volumetric muscle loss (VML) recovery in a rat model using super durable hydrogels derived from bacteria

Bacteria can be programmed to deliver natural materials with defined biological and mechanical properties for controlling cell growth and differentiation. Here, we present an elastic, resilient and bioactive polysaccharide derived from the extracellular matrix of Pantoea sp. BCCS 001. Specifically, it was methacrylated to generate a new photo crosslinkable hydrogel that we coined Pantoan Methacrylate or put simply PAMA. We have used it for the first time as a tissue engineering hydrogel to treat VML injuries in rats. The crosslinked PAMA hydrogel was super elastic with a recovery nearing 100 %, while mimicking the mechanical stiffness of native muscle. After inclusion of thiolated gelatin via a Michaelis reaction with acrylate groups on PAMA we could also guide muscle progenitor cells into fused and aligned tubes – something reminiscent of mature muscle cells. These results were complemented by sarcomeric alpha-actinin immunostaining studies. Importantly, the implanted hydrogels exhibited almost 2-fold more muscle formation and 50 % less fibrous tissue formation compared to untreated rat groups. In vivo inflammation and toxicity assays likewise gave rise to positive results confirming the biocompatibility of this new biomaterial system. Overall, our results demonstrate that programmable polysaccharides derived from bacteria can be used to further advance the field of tissue engineering. In greater detail, they could in the foreseeable future be used in practical therapies against VML

Highly flexible tissue adhesives based on protein by-products

info:eu-repo/semantics/nonPublishe

Combination Therapy of Killing Diseases by Injectable Hydrogels : From Concept to Medical Applications

The complexity of hard‐to‐treat diseases strongly undermines the therapeutic potential of available treatment options. Therefore, a paradigm shift from monotherapy toward combination therapy has been observed in clinical research to improve the efficiency of available treatment options. The advantages of combination therapy include the possibility of synchronous alteration of different biological pathways, reducing the required effective therapeutic dose, reducing drug resistance, and lowering the overall costs of treatment. The tunable physical properties, excellent biocompatibility, facile preparation, and ease of administration with minimal invasiveness of injectable hydrogels (IHs) have made them excellent candidates to solve the clinical and pharmacological limitations of present systems for multitherapy by direct delivery of therapeutic payloads and improving therapeutic responses through the formation of depots containing drugs, genes, cells, or a combination of them in the body after a single injection. In this review, currently available methods for the design and fabrication of IHs are systematically discussed in the first section. Next, as a step toward establishing IHs for future multimodal synergistic therapies, recent advances in cancer combination therapy, wound healing, and tissue engineering are addressed in detail in the following sections. Finally, opportunities and challenges associated with IHs for multitherapy are listed and further discussed.Peer reviewe

Tannic acid: a versatile polyphenol for design of biomedical hydrogels

Tannic acid (TA), a natural polyphenol, is a hydrolysable amphiphilic tannin derivative of gallic acid with several galloyl groups in its structure. Tannic acid interacts with various organic, inorganic, hydrophilic, and hydrophobic materials such as proteins and polysaccharides via hydrogen bonding, electrostatic, coordinative bonding, and hydrophobic interactions. Tannic acid has been studied for various biomedical applications as a natural crosslinker with anti-inflammatory, antibacterial, and anticancer activities. In this review, we focus on TA-based hydrogels for biomaterials engineering to help biomaterials scientists and engineers better realize TA's potential in the design and fabrication of novel hydrogel biomaterials. The interactions of TA with various natural or synthetic compounds are deliberated, discussing parameters that affect TA-material interactions thus providing a fundamental set of criteria for utilizing TA in hydrogels for tissue healing and regeneration. The review also discusses the merits and demerits of using TA in developing hydrogels either through direct incorporation in the hydrogel formulation or indirectly via immersing the final product in a TA solution. In general, TA is a natural bioactive molecule with diverse potential for engineering biomedical hydrogels.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Biosynthesis of exopolysaccharide from waste molasses using <i>Pantoea </i>sp. BCCS 001 GH:a kinetic and optimization study

The bacterium Pantoea sp. BCCS 001 GH produces an exopolysaccharide (EPS) named Pantoan through using sugar beet molasses (SBM) as an inexpensive and widely available carbon source. This study aims to investigate the kinetics and optimization of the Pantoan biosynthesis using Pantoea sp. BCCS 001 GH in submerged culture. During kinetics studies, the logistic model and Luedeking–Piret equation are precisely fit with the obtained experimental data. The response surface methodology (RSM)-central composite design (CCD) method is applied to evaluate the effects of four factors (SBM, peptone, Na2HPO4, and Triton X-100) on the concentration of Pantoan in batch culture of Pantoea sp. BCCS 001 GH. The experimental and predicted maximum Pantoan production yields are found 9.9 ± 0.5 and 10.30 g/L, respectively, and the best prediction factor concentrations are achieved at 31.5 g/L SBM, 2.73 g/L peptone, 3 g/L Na2HPO4, and 0.32 g/L Triton X-100 after 48 h of submerged culture fermentation, at 30 °C. The functional groups and major monosaccharides (glucose and galactose) of a purified Pantoan are described and confirmed by 1HNMR and FTIR. The produced Pantoan is also characterized by thermogravimetric analysis and the rheological properties of the biopolymer are investigated. The present work guides the design and optimization of the Pantoea sp. BCCS 001 GH culture media, to be fine-tuned and applied to invaluable EPS, which can be applicable in food and biotechnology applications.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

An injectable, self-healing, 3D printable, double network co-enzymatically crosslinked hydrogel using marine poly- and oligo-saccharides for wound healing application

In this study, we designed dual network hydrogels with antioxidant and antibacterial activities using marine poly- and oligosaccharides with skin wound healing potential. The synergy between dual enzymatic co-crosslinking based on glucose oxidize (GOx)/horseradish peroxidase (HRP) and electrostatic interaction between positively charged chitooligosaccharides (COS) and phenolated chitosan with negatively charged phenolated alginate formed a hydrogel. The Gel-COS hydrogels exhibited toughness, self-healing, moldability, injectability, and 3D printability. Investigation of the physicochemical properties of the hydrogels exhibited a swelling ratio (< 50%) and in vitro biodegradation after 9 days. Furthermore, the hydrogels exhibited antioxidant properties and antibacterial activity against E. coli and S. aureus. The hydrogels were not cytotoxic and enhanced the migration of 3D cell encapsulated 3T3-L1 fibroblasts, blood vessel formation, as well as in vivo wound healing in a rat model. The Gel-COS hydrogel can be considered a promising skin wound dressing material.SCOPUS: ar.jinfo:eu-repo/semantics/publishe