Development of carrageenan-immobilized lytic coliphage vB_Eco2571-YU1 hydrogel for topical delivery of bacteriophages in wound dressing applications.

Bacteriophages are employed as cost-effective and efficient antibacterial agents to counter the emergence of antibiotic-resistant bacteria and other host bacteria in phage therapy. The increasing incidence of skin wounds is a significant concern in clinical practice, especially considering the limitations of antibiotic therapy. Furthermore, the lack of an effective delivery system that preserves the stability of bacteriophages hampers their clinical implementation. In recent years, there has been a growing amount of research on bacteriophage applications in veterinary and biomedical sciences. In our study, lytic coliphage vB_Eco2571-YU1 was isolated against pathogenic Escherichia coli host bacteria, and hydrogel wound dressing materials were fabricated with marine polysaccharide carrageenan (carr-vB_Eco2571-YU1) for their antibacterial activity. Transmission electron microscopy (TEM) morphology identified it as a Myoviridae coliphage with an icosahedral head length and width of approximately 60 and 56.8 nm, respectively, and a tail length of 119.7 nm. The one-step growth curve of coliphage revealed a latent period of 10 min, a rise period of 15 min, and a burst size of 120 virions per cell. The bacteriolytic activity of unimmobilized coliphages was observed within 2 h; however, strain-specific phage resistance was acquired after 9 h. In contrast, carr-vB_Eco2571-YU1 showed a sharp decline in the growth of bacteria in the log phase after 2 h and did not allow for the acquisition of phage resistance by the E. coli strain. The stability of coliphage under different pH, temperature, osmolarity, detergents, and organic solvents was evaluated. We also studied the long-term storage of carr-vB_Eco2571-YU1 hydrogels at 4 °C and found that the titer value decreased during a time-dependent period of 28 days. These hydrogels were also found to be hemocompatible using a hemolysis assay. The addition of plasticizer (0.6 % (w/v)) to the carrageenan (2 % (w/v)) to prepare carr-vB_Eco2571-YU1 hydrogels showed a decrease in compressive strength with enhanced elasticity. This phage therapy using polymeric immobilization of bacteriophages is a promising next-generation wound dressing biomaterial alternative to conventional wound and skin care management.

Antibacterial, biocompatible, hemostatic, and tissue adhesive hydrogels based on fungal-derived carboxymethyl chitosan-reduced graphene oxide-polydopamine for wound healing applications.

In this study, we developed biocompatible, fungus-derived carboxymethyl chitosan (FCMCS)-reduced graphene oxide (rGO)-polydopamine (PDA)-polyacrylamide (PAM) (FC-rGO-PDA) hydrogels with excellent antibacterial, hemostatic, and tissue adhesive properties for wound healing applications. FC-rGO-PDA hydrogels were prepared by the alkali-induced polymerization of DA followed by the incorporation of GO and its reduction during the polymerization AM to form a homogeneously dispersed PAM network structure in FCMCS solution. The formation of rGO was verified using UV-Vis spectra. The physicochemical properties of hydrogels were characterized by FTIR, and SEM, water contact angle measurements, and compressive studies. SEM and contact angle measurements showed that hydrogels were hydrophilic with interconnected pores and a fibrous topology. In addition, hydrogels adhered well to porcine skin with an adhesion strength of 32.6 ± 1.3 kPa, . The hydrogels exhibited viscoelastic, good compressive (77.5 kPa), swelling, and biodegradation properties. An in vitro study using skin fibroblasts and keratinocytes cells showed the hydrogel had good biocompatibility. Testing against two model bacteria, viz. Staphylococcus aureus and E. coli revealed that the FC-rGO-PDA hydrogel has antibacterial activity. Furthermore, the hydrogel exhibited hemostasis properties. Overall, the developed FC-rGO-PDA hydrogel has antibacterial and hemostasis properties, high water holding capacity, and excellent tissue adhesive properties, which make it a promising candidate for wound healing applications.

A review on directional muscle cell growth in scaffolding biomaterials with aligned porous structures for cultivated meat production.

Scaffolds suitable for use in food products are essential in cultured meat production. Simultaneously, efforts are being undertaken to strengthen the scaffolding to improve cell proliferation, differentiation, and tissue formation. Muscle cells proliferate and differentiate according to the directional patterns of the scaffold, similar to natural tissue and native muscle tissue. Therefore, establishing an aligned pattern in the scaffolding architecture is vital for cultured meat applications. Recent studies on the fabrication of scaffolds with aligned porosity structures and their utility in manufacturing cultured meat are highlighted in this review. In addition, the directional growth of muscle cells in terms of proliferation and differentiation has also been explored, along with the aligned scaffolding architectures. The aligned porosity architecture of the scaffolds supports the texture and quality of meat-like structures. Although it is difficult to build adequate scaffolds for culturing meat manufactured from diverse biopolymers, it is necessary to develop novel methods to create aligned scaffolding structures. Furthermore, to avoid animal slaughter in the future, it will be imperative to adopt non-animal-based biomaterials, growth factors, and serum-free media conditions for quality meat production.

In Situ Synthesis of Environmentally Friendly Waterborne Polyurethane Extended with Regenerated Cellulose Nanoparticles for Enhanced Mechanical Performances.

The development of waterborne polyurethane (WPU) has been stimulated as an alternative to solvent-based polyurethanes due to low-VOC alternatives and reduced exposure to solvents. However, their relatively low mechanical performance and degradation have presented challenges in their wide application. Here, we developed environmentally-friendly bio polyol-based WPU nanocomposite dispersions and films, and presented the optimal process conditions for their manufacture. Additionally, the condition was established without using harmful catalysts or ethyl methyl ketone (MEK) during the polymerization. Moreover, regenerated cellulose nanoparticles (RCNs) were employed as natural chain-extenders in order to improve the biodegradability and mechanical performances of the nanocomposite films. The RCNs have a lower crystallinity compared to cellulose nanocrystals (CNCs), allowing them to possess high toughness without interfering with the elastomeric properties of polyurethane. The prepared CWPU/RCNs nanocomposite films exhibited high toughness of 58.8 ± 3 kgf∙mm and elongation at break of 240 ± 20%. In addition, depending on the molar ratio of NCO/OH, the polyurethane particle size is variously controlled from 70 to 230 nm, enabling to fabricate their dispersions with various transmittances. We believe that our findings not only open a meaningful path toward green elastomers with biodegradability but provides the design concept for bio-elastomers in order to develop industrial elastomers with mechanical and thermal properties.

Effect of Grape Seed Extract on Gelatin-Based Edible 3D-Hydrogels for Cultured Meat Application.

Cell-cultured meat, which is artificial meat made by in vitro cultivation of animal-derived cells, has attracted a lot of interest as a potential source of protein in the future. Porous hydrogels are crucial components that can be used as an artificial extracellular matrix (ECM) to provide cell growth for generating cultured meat. In this study, we highlight the effects of grape seed extract (proanthocyanidins, PC) on the physicochemical and biological functions (bovine satellite muscle cell (BSC) growth and adhesion) of an edible gelatin (GL)-based hydrogel. The freeze-dried hydrogels had good compressive characteristics with pore sizes ranging from 100 to 300 µm. BSCs were able to grow and attach to porous GL-PC hydrogels. These studies suggested that the developed hydrogels using edible materials and made by employing a low-cost method may serve in the cell growth of muscle cells for cultured meat applications.

Synthesis and Characterization of Biopolyol-Based Waterborne Polyurethane Modified through Complexation with Chitosan.

In this study, a series of castor oil-based anionic waterborne polyurethane (CWPU) systems, which it has been suggested may be suitable for use as green elastomers with diverse applications in films and coatings, was prepared by modified with O-carboxymethyl chitosan (CS) as not only a reinforcing filler, but a chain-extender of polyurethane prepolymer to enhance the properties of polyurethanes. Moreover, not only was the system obtained with castor oil-based polyol in the absence of a catalyst, but it was maintained with low viscosity by using acetone instead of toxic methyl ethyl ketone (MEK) during the synthesis process. The sizes, zeta potential, chemical formation, and morphology of the CWPU-CS composites had been investigated by dynamic light scattering (DLS), infrared spectroscopy (IR), and scanning electron microscopy (SEM). Moreover, the results show that the modification allows to enhance storage/loss modulus, tensile properties, thermal stability at high temperature, and biocompatibility of CWPU and CWPU/CS nanocomposites according to various contents of CS.

Bacterial Cellulose and Its Applications.

The sharp increase in the use of cellulose seems to be in increasing demand in wood; much more research related to sustainable or alternative materials is necessary as a lot of the arable land and natural resources use is unsustainable. In accordance, attention has focused on bacterial cellulose as a new functional material. It possesses a three-dimensional, gelatinous structure consisting of cellulose with mechanical and thermal properties. Moreover, while a plant-originated cellulose is composed of cellulose, hemi-cellulose, and lignin, bacterial cellulose attributable to the composition of a pure cellulose nanofiber mesh spun is not necessary in the elimination of other components. Moreover, due to its hydrophilic nature caused by binding water, consequently being a hydrogel as well as biocompatibility, it has only not only used in medical fields including artificial skin, cartilage, vessel, and wound dressing, but also in delivery; some products have even been commercialized. In addition, it is widely used in various technologies including food, paper, textile, electronic and electrical applications, and is being considered as a highly versatile green material with tremendous potential. However, many efforts have been conducted for the evolution of novel and sophisticated materials with environmental affinity, which accompany the empowerment and enhancement of specific properties. In this review article, we summarized only industry and research status regarding BC and contemplated its potential in the use of BC.

Revised Manuscript with Corrections: Polyurethane-Based Conductive Composites: From Synthesis to Applications.

The purpose of this review article is to outline the extended applications of polyurethane (PU)-based nanocomposites incorporated with conductive polymeric particles as well as to condense an outline on the chemistry and fabrication of polyurethanes (PUs). Additionally, we discuss related research trends of PU-based conducting materials for EMI shielding, sensors, coating, films, and foams, in particular those from the past 10 years. PU is generally an electrical insulator and behaves as a dielectric material. The electrical conductivity of PU is imparted by the addition of metal nanoparticles, and increases with the enhancing aspect ratio and ordering in structure, as happens in the case of conducting polymer fibrils or reduced graphene oxide (rGO). Nanocomposites with good electrical conductivity exhibit noticeable changes based on the remarkable electric properties of nanomaterials such as graphene, RGO, and multi-walled carbon nanotubes (MWCNTs). Recently, conducting polymers, including PANI, PPY, PTh, and their derivatives, have been popularly engaged as incorporated fillers into PU substrates. This review also discusses additional challenges and future-oriented perspectives combined with here-and-now practicableness.

The Nanofication and Functionalization of Bacterial Cellulose and Its Applications.

Since economic and environmental issues have become critical in the last several years, the amount of sustainable bio-based production has increased. In this article, microbial polysaccharides, including bacterial cellulose (BC), are analyzed as promising resources with the potential for applications in biofields and non-biofields. Many scientists have established various methods of BC production, nanofication, and functionalization. In particular, this review will address the essential advances in recent years focusing on nanofication methods and nanoficated BC applications as well as functionalization methods and functionalized BC applications.

Biofabrication of Lysinibacillus sphaericus-reduced graphene oxide in three-dimensional polyacrylamide/carbon nanocomposite hydrogels for skin tissue engineering.

The biological synthesis of reduced graphene oxide (rGO) from graphene oxide (GO) is an emerging phenomenon for developing biocompatible nanomaterials for its potential applications in nanomedicine. In this study, we demonstrated a simple, green, and non-toxic method for graphene synthesis using the live biomass of Lysinibacillus sphaericus as the reducing and stabilizing agent under ambient conditions. Ultraviolet-visible spectroscopic analysis confirmed the formation of graphene from GO suspension. X-ray diffraction studies showed the disappearance of the GO peak and the appearance of characteristic graphene broad peak at 2θ = 22.8°. Infrared analysis showed the decrease/disappearance of peaks corresponding to the oxygen-containing functionalities, and appearance of a peak at 1620 cm-1 from unoxidized graphitic domains. Scanning electron microscopic images showed that L. sphaericus-reduced graphene oxide (L-rGO) contains aggregated graphene nanoflakes. Evaluation of the in vitro cytotoxicity of L-rGO nanosheets on human skin fibroblasts using the WST-1 assay did not show any significant effects after 24 h of exposure, which is indicative of biocompatibility. Polyacrylamide hydrogels with L-rGO were synthesized and used as scaffolds to support the growth and proliferation of skin fibroblasts. Cell viability assays and DAPI staining showed proliferation of fibroblasts and exhibited 83% of cell viability even after 28 days. Biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus was enhanced in nanocomposite hydrogels in the presence of 0.25 mg/mL GO and L-rGO in 48 h. Overall, this study showed that microbially-synthesized L-rGO can be used as a dopant in polymeric scaffolds for tissue engineering and highlighted their role in biofilm formation.

One-Pot Processing of Regenerated Cellulose Nanoparticles/Waterborne Polyurethane Nanocomposite for Eco-friendly Polyurethane Matrix.

Regenerated cellulose nanoparticles (RCNs) reinforced waterborne polyurethanes (WPU) were developed to improve mechanical properties as well as biodegradability by using a facile, eco-friendly approach, and introducing much stronger chemical bonding than common physical bonding between RCNs and WPU. Firstly, RCNs which have an effect on improving the solubility and stability of a solution, thereby resulting in lower crystallinity, were fabricated by using a NaOH/urea solution. In addition, the stronger chemical bond between RCNs and WPU was here introduced by regarding at which stage in particular added RCNs worked best on strengthening their bond in the process of WPU synthesis. The chemical structure, mechanical, particle size and distribution, viscosity, and thermal properties of the resultant RCNs/WPU nanocomposites were investigated by Fourier transform infrared analysis (FTIR), Zeta-potential analysis, viscometer, thermogravimetric analysis (TGA), Instron, and dynamic mechanical analysis (DMA). The results of all characterizations indicated that the RCNs/WPU-DMF associated with the addition of RCNs in DMF-dispersed step resulted in more effectively crosslinked between WPU and nano-fillers of nanocellulose particles in the dispersion than Acetone and Water-dispersed steps, thereby attributing to novel interactions formed between RCNs and WPU.

Advances in Protein-Based Materials: From Origin to Novel Biomaterials.

Biomaterials play a very important role in biomedicine and tissue engineering where they directly affect the cellular activities and their microenvironment . Myriad of techniques have been employed to fabricate a vast number natural, artificial and recombinant polymer s in order to harness these biomaterials in tissue regene ration , drug delivery and various other applications. Despite of tremendous efforts made in this field during last few decades, advanced and new generation biomaterials are still lacking. Protein based biomaterials have emerged as an attractive alternatives due to their intrinsic properties like cell to cell interaction , structural support and cellular communications. Several protein based biomaterials like, collagen , keratin , elastin , silk protein and more recently recombinant protein s are being utilized in a number of biomedical and biotechnological processes. These protein-based biomaterials have enormous capabilities, which can completely revolutionize the biomaterial world. In this review, we address an up-to date review on the novel, protein-based biomaterials used for biomedical field including tissue engineering, medical science, regenerative medicine as well as drug delivery. Further, we have also emphasized the novel fabrication techniques associated with protein-based materials and implication of these biomaterials in the domain of biomedical engineering .

Advances in Waterborne Polyurethane-Based Biomaterials for Biomedical Applications.

Polyurethane (PU) is one of the most popular synthetic elastomers and widely employed in biomedical fields owing to the excellent biocompatibility and hemocompatibility known today. In addition, PU is simply prepared and its mechanical properties such as durability, elasticity, elastomer-like character, fatigue resistance, compliance or tolerance in the body during the healing, can be mediated by modifying the chemical structure. Furthermore, modification of bulk and surface by incorporating biomolecules such as anticoagulant s or biorecognizable groups, or hydrophilic/hydrophobic balance is possible through altering chemical groups for PU structure. Such modifications have been designed to improve the acceptance of implant. For these reason, conventional solventborne (solvent-based) PUs have established the standard for high performance systems, and extensively used in medical devices such as dressings, tubing, antibacterial membrane , catheters to total artificial heart and blood contacting materials, etc. However, waterborne polyurethane (WPU) has been developed to improve the process of dissolving PU materials using toxic organic solvents, in which water is used as a dispersing solvent. The prepared WPU materials have many advantages, briefly (1) zero or very low levels of organic solvents, namely environmental-friendly (2) non-toxic, due to absence of isocyanate residues, and (3) good applicability caused by extensive structure/property diversity as well as an environment-friendly fabrication method resulting in increasing applicability. Therefore, WPUs are being in the spotlight as biomaterials used for biomedical applications . The purpose of this review is to introduce an environmental- friendly synthesis of WPU and consider the manufacturing process and application of WPU and/or WPU based nanocomposites as the viewpoint of biomaterials.

Effect of Extracts of Terminalia chebula on Proliferation of Keratinocytes and Fibroblasts Cells: An Alternative Approach for Wound Healing.

Terminalia chebula is one of the traditional medicines used in the treatment of many diseases. In the present work, different concentrations of various organic and aqueous extracts (solvent-free) of T. chebula were tested on fibroblast (L929) and keratinocytes cells to evaluate its biocompatible concentration by using MTT and live-dead viability/cytotoxic assay. These extracts were found to be effective in decreasing the ammonia accumulation in the media, thereby reducing its toxic effect on cells. DPPH assay further confirmed the free-radical scavenging ability of the extracts which increased with the increase in concentration of each extract. Cell proliferation/apoptosis, cytoskeletal structure, and ECM production were further evaluated by live-dead assay and phalloidin/cytokeratin staining, respectively. The cytoskeletal structure and ECM secretion of the cells treated with extracts showed higher cellular activity in comparison to control. In conclusion, we have demonstrated the effect of these extracts of T. chebula on both types of skin cells and optimized concentration in which it could be used as a bioactive component for wound healing applications by increasing cell proliferation and decreasing free-radical production without affecting the normal cellular matrix. It can also find applications in other therapeutics applications where ammonia toxicity is a limiting factor.