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.

A photocrosslinkable and hemostatic bilayer wound dressing based on gelatin methacrylate hydrogel and polyvinyl alcohol foam for skin regeneration.

The enormous potential of multifunctional bilayer wound dressings in various medical interventions for wound healing has led to decades of exploration into this field of medicine. However, it is usually difficult to synthesize a single hydrogel with all the required capabilities simultaneously. This paper proposes a bilayer model with an outer layer intended for hydrogel wound treatment. By adding gelatin methacrylate (GelMA) and tannic acid (TA) to the hydrogel composition and using polyvinyl alcohol-carboxymethyl chitosan (PVA-CMCs) foam layer as supports, a photocrosslinkable hydrogel with an optimal formulation was created. The hydrogels were then examined using a range of analytical procedures, including mechanical testing, rheology, chemical characterization, and in vitro and in vivo tests. The resulting bilayer wound dressing has many desirable properties, namely uniform adhesion and quick crosslinking by UV light. When used against Gram-positive and Gram-negative bacterial strains, bilayer wound dressings demonstrated broad antibacterial efficacy. In bilayer wound dressings with GelMA and TA, better wound healing was observed. Those without these elements showed less effectiveness in healing wounds. Additionally, encouraging collagen production and reducing wound infection has a major therapeutic impact on wounds. The results of this study could have a significant impact on the development of better-performing wound dressings.

Development of Ag NPs/allantoin loaded PCL/GEL electrospun nanofibers for topical wound treatment.

In the present study, the allantoin and silver nanoparticle (Ag NPs) loaded poly caprolactone/gelatin (PCL/GEL) nanofibers produced using electrospinning technique and their cyto-compatibility and wound healing activity were evaluated in vitro and in vivo. The SEM imaging revealed diameters of 278.8 ± 10 and 240.6 ± 12 nm for PCL/GEL/Ag NPs and PCL/GEL/Ag NPs/allantoin scaffolds. The Ag NPs entrapment into scaffolds was evaluated by FTIR analysis and EDX mapping. Both scaffolds containing Ag NPs and Ag NPs/allantoin exhibited valuable wound healing activity in Wistar rat animal model. The profound granulation tissue formation, high collagen deposition in coordination with low level of edema and inflammatory cells in Ag NPs/allantoin loaded scaffolds resulted in complete and mature re-epithelialization in giving the healing score (12 out of 12) equal to positive control group to the wounds treated with these scaffolds. It was concluded that the Ag NPs/allantoin loaded scaffolds regarding to their good antibacterial activity and excellent wound healing activity could be introduced as new effective wound dressing materials.

Metal-coordination synthesis of a natural injectable photoactive hydrogel with antibacterial and blood-aggregating functions for cancer thermotherapy and mild-heating wound repair.

Photothermal therapy (PTT) is a promising approach for treating cancer. However, it suffers from the formation of local lesions and subsequent bacterial infection in the damaged area. To overcome these challenges, the strategy of mild PTT following the high-temperature ablation of tumors is studied to achieve combined tumor suppression, wound healing, and bacterial eradication using a hydrogel. Herein, Bi2S3 nanorods (NRs) are employed as a photothermal agent and coated with hyaluronic acid to obtain BiH NRs with high colloidal stability. These NRs and allantoin are loaded into an injectable Fe3+-coordinated hydrogel composed of sodium alginate (Alg) and Farsi gum (FG), which is extracted from Amygdalus scoparia Spach. The hydrogel can be used for localized cancer therapy by high-temperature PTT, followed by wound repair through the combination of mild hyperthermia and allantoin-mediated induction of cell proliferation. In addition, an outstanding blood clotting effect is observed due to the water-absorbing ability and negative charge of FG and Alg as well as the porous structure of hydrogels. The hydrogels also eradicate infection owing to the local heat generation and intrinsic antimicrobial activity of the NRs. Lastly, in vivo studies reveal an efficient photothermal-based tumor eradication and accelerated wound healing by the hydrogel.

Protein by-products: Composition, extraction, and biomedical applications.

Significant upsurge in animal by-products such as skin, bones, wool, hides, feathers, and fats has become a global challenge and, if not properly disposed of, can spread contamination and viral diseases. Animal by-products are rich in proteins, which can be used as nutritional, pharmacologically functional ingredients, and biomedical materials. Therefore, recycling these abundant and renewable by-products and extracting high value-added components from them is a sustainable approach to reclaim animal by-products while addressing scarce landfill resources. This article appraises the most recent studies conducted in the last five years on animal-derived proteins' separation and biomedical application. The effort encompasses an introduction about the composition, an overview of the extraction and purification methods, and the broad range of biomedical applications of these ensuing proteins.

North by Southwest: Screening the Naturally Isolated Microalgal Strains from Different Habitats of Iran for Various Pharmaceutical and Biotechnology Applications.

Background and Aims: Microalgae are known as a promising source for food, pharmaceutical, and biofuel production while providing environmental advantages. The present study evaluates some newly isolated microalgal strains from north and southwest of Iran as a potential source for high-value products. Methods: Primitive screening was carried out regarding growth parameters. The molecular and morphological identifications of the selected strains were performed using 18S rRNA gene sequencing. After phylogenic and evolutionary studies, the selected microalgal strains were characterized in terms of protein and pigment content, in addition to the fatty acid profile content. Besides, the CO2 fixation rate was determined to assess capability for various environmental applications. Results: All of the selected strains were predominantly belonging to Scenedesmus sp. and Desmodesmus sp. The isolated Scenedesmus sp. VN 009 possessed the highest productivity content and CO2 fixation rate of 0.054 g·L-1d-1 and 0.1 g·L-1d-1, respectively. Moreover, data from GC/MS analysis demonstrated the high robustness of this strain to produce several valuable fatty acids including α-linolenic acid and linoleic acid in 45% and 20% of total fatty acids. Conclusions: The identified strains have a great but different potential for SCP, ß-carotene, and ω-3 production, as well as CO2 fixation for environmental purposes. In this study, considering the wide range of microalgal strains in different habitats of Iran, the potential applications of native microalgae for various pharmaceutical, food, and biotechnology purposes were investigated.

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.

Biosynthesis of exopolysaccharide from waste molasses using Pantoea 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.

The feasibility of injectable PRF (I-PRF) for bone tissue engineering and its application in oral and maxillofacial reconstruction: From bench to chairside.

Among all the biomaterials introduced in the field of bone tissue engineering, injectable platelet-rich fibrin (I-PRF) has recently gained considerable attention. I-PRF, as a rich source of biologically active molecules, is a potential candidate which can be easily obtained in bedside and constitutes several biological factors which can result in higher anti-bacterial, anti-inflammatory and regenerative capabilities. According to the studies evaluating the osteogenic efficacy of I-PRF, this biomaterial has exhibited favorable outcomes in terms of adhesion, differentiation, migration, proliferation and mineralization potential of stem cells. In addition, the injectability and ease-of-applicability of this biomaterial has led to its various clinical applications in the oral and maxillofacial bone regeneration such as ridge augmentation, sinus floor elevation, cleft palate reconstruction and so on. Furthermore, to enhance the clinical performance of I-PRF, albumin gel-PRF as a long-lasting material for long-term utilization has been recently introduced with a gradual increase in growth factor release pattern. This review provides a comprehensive approach to better evaluate the applicability of I-PRF by separately appraising its performance in in-vitro, in-vivo and clinical situations. The critical approach of this review toward the different production protocols and different physical and biological aspects of I-PRF can pave the way for future studies to better assess the efficacy of I-PRF in bone regeneration.

Avian Egg: A Multifaceted Biomaterial for Tissue Engineering.

Most components in avian eggs, offering a natural and environmentally friendly source of raw materials, hold great potential in tissue engineering. An avian egg consists of several beneficial elements: the protective eggshell, the eggshell membrane, the egg white (albumen), and the egg yolk (vitellus). The eggshell is mostly composed of calcium carbonate and has intrinsic biological properties that stimulate bone repair. It is a suitable precursor for the synthesis of hydroxyapatite and calcium phosphate, which are particularly relevant for bone tissue engineering. The eggshell membrane is a thin protein-based layer with a fibrous structure and is constituted of several valuable biopolymers, such as collagen and hyaluronic acid, that are also found in the human extracellular matrix. As a result, the eggshell membrane has found several applications in skin tissue repair and regeneration. The egg white is a protein-rich material that is under investigation for the design of functional protein-based hydrogel scaffolds. The egg yolk, mostly composed of lipids but also diverse essential nutrients (e.g., proteins, minerals, vitamins), has potential applications in wound healing and bone tissue engineering. This review summarizes the advantages and status of each egg component in tissue engineering and regenerative medicine, but also covers their current limitations and future perspectives.

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.

In vitro and in vivo Evaluation of Succinic Acid-Substituted Mesoporous Silica for Ammonia Adsorption: Potential Application in the Management of Hepatic Encephalopathy.

PURPOSE: Hepatic encephalopathy (HE) is a critical situation in which liver failure affects brain function. HE could result in a state of coma and death. The liver is the main organ for ammonium ion (NH4 +) metabolism. Hence, acute and/or chronic liver failure could lead to hyperammonemia. NH4 + is the most suspected neurotoxic agent in HE. Thus, finding new therapeutic options to decrease plasma and brain NH4 + levels has a significant clinical value. Mesoporous silica (MS) particles have revolutionized many aspects of pharmaceutical sciences, including drug delivery systems. Moreover, recently, MS has been applied as agents for the detoxification of chemicals (eg, drugs and poisons). METHODS: First, MS particles containing amine groups (MS-NH2) were synthesized in co-condensation processes. Then, the structure was modified by succinic anhydride to have MS-SA. The MS-SA was characterized (FT-IR, XRD, X-ray photoelectron spectroscopy (XPS), DLS-Zeta FESEM-EDX, and HRTEM). Then, the potential of MS-NH2 and MS-SA particles in adsorption of NH4 + was investigated in vitro and in vivo. MS-NH2 and MS-SA were incubated with increasing concentrations (0.1-10 mM) of NH4 +, and the scavenging capacity of the investigated particles was evaluated. On the other hand, different doses (1 and 5 mg/kg per day) of nanoparticles were administered to a hyperammonemia animal model. RESULTS: It was figured out that both MS-NH2 and MS-SA significantly scavenged NH4 + in the in vitro model. However, the NH4 + scavenging capability of MS-SA was more significant. Administration of MS-NH2 and MS-SA also considerably decreased the level of ammonium in plasma and brain and improved cognitive and locomotor activity in hyperammonemic animals. The effects of MS-SA were more significant than MS-NH2 in the HE animal model. CONCLUSION: Collectively, our data suggest that MS particles, especially succinic acid-functionalized MS, could act as special ancillary treatment in HE as a critical clinical complication.

Enterobacter sp. Mediated Synthesis of Biocompatible Nanostructured Iron-Polysaccharide Complexes: a Nutritional Supplement for Iron-Deficiency Anemia.

FDA has approved iron oxide nanoparticles (IONs) coated with organic compounds as a safe material with less toxic effects compared with the naked metal ions and nanoparticles. In this study, the biological and physicochemical characteristics of a nanostructured iron-polysaccharide complexes (Nano-IPC) biosynthesized by Enterobacter sp. were evaluated. Furthermore, the serum biochemical parameters, tissue iron level, red blood cell parameters, and organ ferritin of rats were measured for investigating the effect of the Nano-IPCs in comparison with FeSO4 as a supplement for iron deficiency. The biosafety data demonstrated 35% increment of viability in Hep-G2 hepatocarcinoma cell lines when treated with nanoparticles (500 µg/mL) for 24 h. Besides, iron concentration in serum and tissue as well as the expression of ferritin L subunit in animals treated with the Nano-IPCs supplement were meaningfully higher than the FeSO4-supplemented and negative control animals. Moreover, the expression level of ferritin H subunit and biochemical factors remained similar to the negative control animals in the Nano-IPC-supplemented group. These results indicated that Nano-IPCs can be considered as a nontoxic supplement for patients carrying iron-deficiency anemia (IDA).

Bacteria-assisted biogreen synthesis of radical scavenging exopolysaccharide-iron complexes: an oral nano-sized nutritional supplement with high in vivo compatibility.

Microbial exopolysaccharides (EPSs) have recently served as an efficient substrate for the production of biocompatible metal nanoparticles (NPs) given their favorable stabilizing and reducing properties due to the presence of polyanionic functional groups in their structure. In the present work, Pantoea sp. BCCS 001 GH was used to produce EPS-stabilized biogenic Fe NPs as a complex through a novel biosynthesis reaction. Physicochemical characterization of the EPS-Fe complex was performed, indicating high thermal stability, desirable magnetic properties due to the uniform distribution of the Fe NPs with the average size of ∼10 nm and spherical shape within the EPS matrix. In addition, the in vivo toxicity of the EPS-stabilized Fe NPs was evaluated to investigate their potential for the treatment of iron deficiency anemia. Biological blood parameters and organ histology studies confirmed very high safety of the biosynthesized composite, making EPS-Fe a suitable candidate with an economical and environment friendly synthesis method for a wide spectrum of potential fields in medicine.

Exopolysaccharide from Pantoea sp. BCCS 001 GH isolated from nectarine fruit: production in submerged culture and preliminary physicochemical characterizations.

Exopolysaccharide (EPS), as potential microbial base polysaccharide source, has plenty of applications due to its unique physicochemical structure. A Pantoea sp. BCCS 001 GH bacterium with the ability to produce a high amount of EPS was identified by 16S rRNA gene sequencing and biochemical tests. The synthesis of EPS by Pantoea sp. BCCS 001 GH was 13.50 g/L in 48 h when sucrose was used as substrate. The proposed protocol was desirably rapid for massive prodcution of EPS and showed the remarkable impact of sucrose and disodium hydrogen phosphate, peptone, Triton x-100 and 2% (v/v) inoculum size on the yields of EPS production. The EPS was mainly composed of glucose and galactose in a relative molar ration (glucose/galactose) of 85.18:14.82, respectively. The preliminary characterization showed the average molecular-weight of EPS is about 2.522 × 106 Da. The microscopics morphology of polymer was formed irregularly shaped structures.

Eexopolysaccharide production of Pantoea sp. BCCS 001 GH: Physical characterizations, emulsification, and antioxidant activities.

The newly discovered exopolysaccharide (EPS) produced by Pantoea sp. BCCS 001 GH, isolated from nectarine fruit and some of its physical properties were characterized. This paper examines precipitation, rheological behavior, emulsification, and antioxidant activities of EPS. Particularly, the concentration of common salt (NaCl) affected on precipitation of EPS; while the low ratio (3 Vagent/V) of CaCl2 isopropanol to culture broth was required. The Zeta potential value of emulsified particles had a high surface charge -65.67 ±â€¯0.6 mV. The strong hydrogen bonds and/or hydrophobic interactions between the polysaccharide and the Congo red molecule showed the triple helical polysaccharide. The water solubility index and water holding capacity of the EPS were 15.6 ±â€¯0.22, 662 ±â€¯12.5%, respectively. The degradation temperature (Td) of 318 °C was observed from the TGA curve for the EPS. The rheological study indicated that the EPS had typically non-Newtonian pseudoplastic behavior. Among the EPS and Tween 80 tested against oils/hydrocarbons, EPS was found to be one the most effective emulsifying agent against kerosene, xylene, hexane and diesel (72.8, 74.5, 68.3 and 81.1%, respectively). It was found that changes in pH (2-12) significantly influenced the emulsification of kerosene and diesel. In vitro antioxidant activity of EPS against hydroxyl, 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH), and superoxide free radicals shown good antioxidant activities. These results indicate the favorable potential of the EPS from strain BCCS 001 GH in food and pharmaceutical fields.

Characterization of biogenic Fe (III)-binding exopolysaccharide nanoparticles produced by Ralstonia sp. SK03.

A new technological approach to nanoparticle synthesis is using microorganisms, such as bacteria, which have the ability to synthesize nontoxic nanoparticles with high biocompatibility. In addition, bacteria have strict control over size, structure, shape, and dimension of produced nanoparticles. In the present work, Fe (III)-binding exopolysaccharide (Fe-EPS) nanoparticles were biosynthesized by Ralstonia pickettii sp. SK03, a bacterium isolated from a mineral spring. 16S rRNA gene sequencing and biochemical tests were done for identification of the isolated bacterium. For the first time, critical biological and physicochemical properties of this iron oxide nanoparticle were characterized using Fourier Transform Infrared (FTIR) Spectroscopy, Transmission Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM), Dynamic Light Scattering (DLS), Thermogravimetric analysis (TGA), X-ray crystallography (XRD), Atomic absorption spectroscopy (AAS), and cell viability assays (MTT assay). The characterization results showed that Fe-EPS nanoparticles were composed of spherical ferrihydrite nanoparticles (with a size range of 1.2-2 nm), trapped in a polysaccharide matrix. The TGA analysis demonstrated that Fe-EPS nanoparticles contained ∼25.2% polysaccharide. Therefore, this polysaccharide matrix showed a very low magnetic saturation value (0.25 emu/g) and a large negative charge of -93.8 mV. In addition, treatment of hepatocarcinoma cell line (Hep-G2) with 1-500 µg/mL concentrations of Fe-EPS nanoparticles caused 40% increase in the cell viability, which indicated that the biosynthesized nanoparticles were nontoxic and biocompatible. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018 © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1167-1176, 2018.

Production of xanthan gum by free and immobilized cells of Xanthomonas campestris and Xanthomonas pelargonii.

Production of xanthan gum using immobilized cells of Xanthomonas campestris and Xanthomonas pelargonii grown on glucose or hydrolyzed starch as carbon sources was investigated. Calcium alginate (CA) and calcium alginate-polyvinyl alcohol-boric acid (CA-PVA) beads were used for the immobilization of cells. Xanthan titers of 8.2 and 9.2g/L were obtained for X. campestris cells immobilized in CA-PVA beads using glucose and hydrolyzed starch, respectively, whereas those for X. pelargonii were 8 and 7.9 g/L, respectively. Immobilized cells in CA-PVA beads were successfully employed in three consecutive cycles for xanthan production without any noticeable degradation of the beads whereas the CA beads were broken after the first cycle. The results of this study suggested that immobilized cells are advantageous over the free cells for xanthan production. Also it was shown that the cells immobilized in CA-PVA beads are more efficient than cells immobilized in CA beads for xanthan production.