Biopolymers最新文献

In this paper, we offer a unique green synthetic approach for producing iron sulfide quantum dots (FeS₂ QD)-chitosan composites using gel chemistry. The technique uses the environmental features of chitosan, a biocompatible and biodegradable polysaccharide, and the excellent electrical properties of FeS₂ QDs. By sustainable chemistry principles, the synthesis process is carried out under gentle settings, using aqueous solutions and avoiding hazardous solvents and strong chemicals. The resulting FeS₂ QD-chitosan composite has superior structural integrity, homogeneous QD distribution, and improved physicochemical characteristics. Comprehensive characterization techniques, such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and photoluminescence spectroscopy, confirm the successful integration of FeS₂ QDs into the chitosan matrix while preserving their quantum properties. This work demonstrates the viability of gel chemistry as a green synthetic technique for generating functional nanocomposites, providing a scalable and environmentally responsible option for advanced material development.

When the kidneys are injured, uremic toxins (UTXs) accumulate in the body, affecting other tissues and causing a loss of essential body functions. This study investigated the adsorption of blood plasma-laden UTXs on the surface of PCL fibers to assess their potential as an alternative to membrane dialysis materials. Using plasma containing 26 UTXs at a concentration similar to that found in end-stage kidney disease patients, we analyzed the adsorbed proteins and examined clot formation in normal and toxin-treated plasma in the presence of PCL fibers. Our findings revealed that the presence of UTXs significantly increased the adsorption of proteins on PCL fiber meshes, without leading to increased clot formation. This suggests a lack of enzymatic activation despite the higher protein adsorption. Additionally, our study indicates that unmodified PCL surfaces have the potential to trigger a strong humoral immune response, underscoring the importance of understanding these interactions for the development of personalized treatment approaches for patients with kidney failure.

Exploring new ecological and simultaneous processes to modify wood fibers (WF) by-products is a required pathway toward circular economy and sustainability. Thus, plasma-activated water (PAW) and ultrasound (U) were employed as alternative methods to modify WF in a continuous process. Such treatments promoted the etching and cavities on the WF surface that destabilized the hydrogen bonds of the hemicellulose and lignin molecules, increasing the cellulose fraction. The addition of modified WF in the PLA matrix increased the storage modulus (2937 up to 5834) and Young modulus (3990 up to 6000 MPa), indicating well fiber/matrix interactions. The results corroborated that the use of modified WF as fillers could reduce the cost of extruded PLA-based composites and expand the production of bio-based materials for the mobility or packaging field.

Cryogels were fabricated by combining polyvinyl alcohol (PVA) and chitosan of varying molecular weights (Mw). In this study, the effects of chitosan Mw, types of boron-containing molecules on network formation, and boron release rate in resulted cryogels were investigated. The PVA/chitosan blend maintained a constant 4.5% (w/v) polymer content. PVA to chitosan weight ratio of 6:1 was maintained and fixed. Five percent w/w boric acid and borax (sodium tetraborate) crosslinkers were added in PVA and chitosan mixtures to construct cryogels. The freeze-dried specimens underwent crosslinking evaluation, chemical composition analysis by FTIR, and boron release studies by ICP-MS. The pore morphology and the swelling capacity of the cryogel have been assessed by SEM and incubation in water, respectively. Mechanical test was also used to evaluate the effect of borax and Mw of chitosan on cryogels' mechanical properties. It was demonstrated that the types of boron supply had a significant role on the cryogelation capability. For different chitosan Mw, the cryogels made using borax showed stable cryogels. In contrast, even after altering the chitosan Mw, the formula with boric acid was unable to create stable cryogels. In addition, boron release assay showed that the quantity of free boron in the incubation solutions decreased as the Mw of the chitosan component of the cryogel was reduced. Cell culture studies with MC3T3-E1 pre-osteoblast cells in the cryogels indicated that borax-crosslinked samples exhibited sustained cell viability. Alizarin red staining assay was used to study mineralization capacity of boron-containing hydrogels, which confirmed increase of mineralization in low molecular weight chitosan groups.

The antibacterial nanofibrous mat is crucial in biomedicine as it enhances infection control, expedites wound healing, and mitigates health hazards by decreasing antibiotic usage. A novel synergistic antibacterial and hydrophilic nanofibrous mat successfully fabricated by solution electrospinning from polyvinyl alcohol (PVA) incorporated Croton bonplandianum Baill (CBB) leaves extract. Antioxidant-enriched leaf extract of the CBB plant was integrated with PVA in varying proportions of 30% (CBB-30), 40% (CBB-40), and 50% (CBB-50) to manufacture antibacterial nanofibrous mat. The zone of inhibition (ZOI) was recorded at 16, 18, and 21 mm for CBB-30, CBB-40, and CBB-50, respectively. The wetted radius, a key parameter for moisture management properties, reached up to 20 mm for CBB-40 and CBB-50. This demonstrates the rapid absorption and quick-drying characteristics, highlighting the exceptional hydrophilicity of the nanofibrous mat. The increased dozing of CBB extract into the PVA also reduced its fiber diameter. The diameters of pure PVA, CBB-30, CBB-40, and CBB-50 were found as 396, 388, 279, and 241 nm, correspondingly. The developed nanofibrous mat, exhibiting ZOI of up to 21 mm, efficient moisture management properties, and a nanoscale fiber diameter of 241 nm, may possess significant uses in the biomedical domain.

Biomaterials with antimicrobial and muco-adhesive properties represent an efficient system for different applications. In this paper, a new biomaterial based on chitosan-camphor beads and their crosslinked form with glutaraldehyde was optimized. Low and high molecular weight chitosan were considered. After an optimization procedure of blank beads preparation, various strategies were used to load camphor into chitosan beads where eight different beads suspensions were characterized for their size and encapsulation efficiency of camphor. Powdered camphor was added to the chitosan solution during the beads preparation or to preformed beads while it was dissolving in water or in 2% acetic acid solution. Results showed that, camphor addition to chitosan solution led to the formation of homogeneous suspensions with reproducible and higher encapsulation efficiencies of camphor compared to the other formulations, irrespective of the chitosan weight. In addition, these beads were stable for 1 month of storage at 4°C. The camphor loaded cross-linked beads with glutaraldehyde (referred to as Cam-beads-GA) were more stable than noncross-linked beads (Cam-beads), which also demonstrated satisfactory stability results. Camphor embedding in chitosan beads was proven to occur through hydrogen bonding and potentially imine bonds by FTIR analysis. The optimized formulations constitute a suitable delivery system for other bioactive agents.

This study aims to evaluate the impact of formulation parameters on tannic acid-crosslinked gelatine (GelTA) films, intended as a mucoadhesive matrix for extended buccal drug delivery. GelTA films were prepared using the solvent evaporation technique and screened based on their mucoadhesive and dissolution characteristics. The formulation variables included the source of gelatine (bovine and fish), tannic acid concentration, pH of the film-forming solutions, and the type and concentration of plasticisers. Subsequently, selected films underwent further characterisation (e.g., crosslinking density, stability) to elucidate their features as a drug delivery matrix. GelTA films exhibited a significantly improved dissolution time compared to the non-crosslinked film (BG-GLY20), while maintaining a substantial water uptake capacity conducive to a matrix system with extended action. The bovine GelTA film containing 5% w/w tannic acid and 20% w/w glycerine, prepared at pH 7 (BG-GLY20-7), exhibited a 1.6-fold increase in mucoadhesivity and an extended dissolution time of up to 6 h compared to BG-GLY20 (control), along with superior antioxidant and antimicrobial properties. However, stability studies indicate the need for an oxygen-free environment for film storage. In conclusion, GelTA films show promise as a buccal film matrix, offering extended dissolution times, substantial water uptake, and enhanced adhesive strength.

Dipeptides were constructed using hydrophobic amino acid residues following AMP prediction. After that Boc-modification was performed on the screened peptides and finally Boc-Phe-Trp-OMe and Boc-Trp-Trp-OMe were synthesized. Even though no inhibition zones were observed in agar well diffusion assays, minimum inhibitory concentration (MIC) analysis revealed anti-bacterial activity against both Gram-positive and Gram-negative bacteria, with MIC₉₀ ranging from 230 to 400 μg/mL. The crystal violet assay confirmed the dipeptides' biofilm eradication and disruption capabilities. Furthermore, membrane permeabilization assays indicated outer and inner membrane permeabilization, while SEM analysis revealed the formation of fibril and spherical nanostructures, likely contributing to this effect. The peptides also exhibited resistance to protein adsorption, non-cytotoxicity, and non-hemolytic properties, making them promising broad-spectrum anti-bacterial agents with biofilm eradication and disruption potential. This study concludes that Boc-protected phenylalanine- and tryptophan-based dipeptides can self-assemble and can be used as broad-spectrum anti-bacterial agents. The self-assembly of these peptides offers a versatile platform for designing biomaterials with tailored properties and functionalities. Research exploring the anti-bacterial potential of Boc-protected dipeptides has been limited, prompting our investigation to shed light on this overlooked area. Our analysis of synthesized Boc-protected dipeptides revealed notable anti-bacterial activity, marking a significant advancement. This finding suggests that these dipeptides could emerge as potent, broad-spectrum anti-bacterial agents, addressing the urgent need for effective treatments against bacterial resistance and opening new avenues in therapy. This study not only enhances our understanding of these dipeptides but also highlights their potential as innovative and efficacious anti-bacterial agents, making a substantial impact in the clinical field.

One of the current biotechnological applications is nanofiber applications made from algae using the electrospinning technique. Nanofibers containing poly-caprolactone (PCL) extracted from the brown seaweed Hijiki (Sargassum fusiforme) were prepared using electrospinning technique. Water extraction was performed to preserve the integrity of Hijiki components, ensuring their efficacy in subsequent electrospinning and characterization. The morphology and chemical composition of the nanofibers were characterized using field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) analyses. Hijiki was found to combine well with electrospun biocompatible polymers and effectively provide the common properties of these materials. The cytotoxicity of algae-doped PCL nanofibers was examined in vitro using liver cancer and liver healthy cell lines (HepG2 and The-2). Among hepatic tumor cell lines, the HepG2 cell line has been preferred due to its wide range of scientific applications. Although the nanofibers caused a 28% decrease in liver cancer cell lines viability (HepG2), the decrease in healthy liver cell viability (The-2) was 12%. Algae-doped PCL nanofiber applied to bacteria showed antibacterial effect. Based on the findings, Hijiki macroalgae nanofibers show great promise for tissue regeneration and band-aid applications in the medical industry.