Biopolymers最新文献

Periodontitis is a bacterial infectious disease. Photodynamic therapy (PDT) offers high selectivity, drug-resistance-free treatment, and immune regulation. The second-generation porphyrin photosensitizer Ce6 excels in reactive oxygen species (ROS) production. However, periodontitis pathogens' negative charge limits Ce6's interaction with them. This study prepared a modified cationic cyclodextrin (sPAM) and encapsulated Ce6 in an aqueous medium to create a nano-photodynamic system (Ce6@sPAM), which was characterized. In vitro evaluations assessed Ce6@sPAM's photodynamic performance, safety, antibacterial properties, and effects on immunoregulation. TEM images revealed Ce6@sPAM's irregular spherical shape, with a size of 236 nm by DLS and a Zeta potential of +16.4 mV. Ce6@sPAM exhibits a notably brief light half-life of merely 13 min, facilitating its swift in vivo clearance. SOSG and DCFH-DA fluorescence experiments showed Ce6@sPAM had stronger ROS generation (p < 0.05) and better bacterial penetration (p > 0.05) than Ce6. Co-incubation with Ce6@sPAM reversed bacterial surface potential from negative to positive. Bio-safety tests confirmed its excellent biocompatibility. In antibacterial tests, sPAM showed antibacterial properties, and Ce6@sPAM had a stronger effect than Ce6 under light (p < 0.001). Ce6@sPAM also exhibited high macrophage killing rates (> 90%) without specificity (p > 0.05) and can induce M1 macrophages to M2 polarization. Ce6-loaded modified cyclodextrin nanoparticles hold great promise for synergistic PDT in periodontitis treatment, especially in early stages for optimal immunomodulation.

In this study, the effect of microwave (MW) treatment on obtaining barley microfibers and their effect on the chemical, structural, and viscoelastic properties of films based on starch (S) and polyvinyl alcohol (P) was inspected. SEM, FTIR, and TGA analysis revealed that MW treatment effectively achieves the defibrillation and the destabilization of hydrogen bonds of the hemicellulose and lignin molecules, resulting in the obtention of barley microfibers (BM). XPS analysis allowed identification of the oxidation and crosslinking mechanism of S, P, and S/P films containing BM during the extrusion process. PBM and SPBM films showed an increase in CC proportions linked to the crosslinking phenomena and promoted stronger OCO interactions, which increased the storage modulus from 195.5 to 380.8 MPa and from 78.0 to 134 MPa, respectively. Conversely, SBM showed lower interactions CC and high COH bonds that reduced the component adhesion. Thus, the matrix type and extrusion process determined the chemical interaction with BM, resulting in films with different rigidity that can be useful in different sustainable packaging solutions.

Bacterial biofilms are complex, multi-component structures consisting primarily of four key elements: polysaccharides, metal ions, proteins, and extracellular DNA. In our research, we specifically focus on the polysaccharide and metal ion components, which play a crucial role in determining the biofilm's mechanical properties. Polysaccharides provide the structural matrix, although metal ions, particularly divalent cations like calcium and cobalt, cross-link with the polysaccharides, thereby modulating the biofilm's rigidity and viscoelastic behavior. By introducing divalent cations into nanocellulose, we can replicate this natural cross-linking process, allowing us to finely tune the material's mechanical properties to more closely resemble those of bacterial biofilms. This approach not only enhances the accuracy of synthetic biofilm models over alginate hydrogels but also provides valuable insights into how biofilms maintain their structural integrity in various environments. Our findings indicate that nanocellulose exhibits mechanical properties closer to biofilms than alginate analogs, making it a suitable non-living control for biofilm studies. Furthermore, divalent nickel, followed by calcium and magnesium, demonstrate a closer mechanical mimicry to biofilms. In conclusion, this research shows the potential of nanocellulose as a versatile material for bacterial biofilm mimicry.

Skin aging is a multifaceted process marked by the destruction of skin structure and the diminishment of skin function, significantly impacting both physical and mental health. Injectable hydrogels are promising for skin repair, but chemical crosslinking in most hydrogels can cause cytotoxicity, whereas agarose hydrogels avoid crosslinking yet face injectability challenges. We have herein developed green agarose hydrogel implants with high biocompatibility for skin repair and regeneration in photoaged skin. The hydrogel is prepared by utilizing agarose's ability to dissolve at high temperatures and gel at low temperatures. This process yields implants with particle sizes predominantly ranging from 100 to 150 μm. The agarose hydrogel implant exhibits excellent injectability, with a steady injection force curve consistently around 4 N. The agarose hydrogel implant promotes the proliferation of human dermal fibroblasts and does not induce hemolysis or pyrogenic reactions. In a photoaging mouse model, the agarose hydrogel implant improves skin density and hydration, reduces transepidermal water loss, and stimulates collagen regeneration. This agarose hydrogel implant provides a novel approach to repairing aged skin and holds significant potential in the fields of skin health and tissue regeneration.

Hepatocellular carcinoma (HCC) is one serious cause of cancer-associated deaths worldwide. Poor bioavailability and non-specific targeting of drugs is a challenge. Gemcitabine (GEM) is broad-spectrum anticancer drug for liver and other cancers. In this study, an attempt to formulate drug-loaded galactosylated albumin-based nanoparticles (GEM-LA-BSA NPs) was made to increase the bioavailability and targetability of hydrophilic drugs. The formulation was optimized using central composite design for further evaluation and developed a pilot-scale approach for commercialization. LA-BSA conjugate was synthesized, characterized, and formulated into a nanoformulation. The particle size of the optimal formulation was 40.19 ± 7.98 nm with reduced drug release (57.78% ± 4.10%) in 48 h and aggregates-like structure by HR-TEM. In vitro studies in HepG2 cells indicated better cytotoxicity of GEM-LA-BSA NPs than GEM (IC₅₀ values 226.42 ± 11.32 and 366.03 ± 11.93 μg/mL, respectively), while in vivo studies in SD rats exhibited almost two-fold bioavailability, better pharmacokinetics, and reduced IC50 portraying immense potential as an effective drug delivery system.

Inflammation is a hallmark of various pathological conditions, including cancer, cardiovascular diseases, neurodegenerative disorders, and autoimmune diseases. Reactive oxygen species (ROS) are crucial mediators in the inflammatory microenvironment, playing a pivotal role in both normal cellular processes and disease progression. Targeting ROS overproduction in inflamed tissues has emerged as a promising therapeutic strategy. Polymeric nanoparticles (NPs) responsive to ROS levels in pathological tissues have gained substantial attention as precision drug delivery systems, capable of ensuring controlled, site-specific drug release. This review provides a comprehensive mechanistic insight into ROS-responsive polymeric nanoparticles, examining their structural design, functionalization strategies, drug release mechanisms, and potential for targeted therapies in inflammatory conditions. Furthermore, we discuss recent advancements, challenges, and future directions in utilizing ROS-responsive polymeric nanoparticles for precision therapeutics, highlighting their transformative potential in clinical applications.

This study investigates the properties of a biocomposite film made from gelatin and sustainably sourced keratin incorporating chitosan-functionalized silver nanoparticles. Varied concentrations of chitosan solution (i.e., 0.4%, 0.6%, 0.8%, and 1% w/v) were used in the synthesis of silver nanoparticles, and their particle size, distribution, and antibacterial and antifungal activities were evaluated against foodborne pathogens (Escherichia coli, Staphylococcus aureus, Rhizopus stolonifer, and Aspergillus niger). The addition of keratin enhanced the film's tensile strength to 16.64 MPa, a 403% increase compared to the gelatin film. However, incorporating 2% chitosan functionalized silver nanoparticles reduced the tensile strength to 9.07 MPa compared to the Gelatin-Keratin film. The distribution of nanoparticles and the interaction between the polymer chains were analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. The composite films also exhibited significant UV blocking efficiency, achieving 99% blockage of ultraviolet A and 100% blockage of ultraviolet B. The biocompatibility of the films was tested with MG63 cell lines, showing that silver nanoparticle concentrations (0.3%–2%) improved cell viability to 87% after 96 h of incubation. These findings reveal that the bionanocomposite films exhibit strong antibacterial and antifungal properties, along with excellent biocompatibility, making them ideal materials for wound healing and tissue engineering applications.

Microbial resistance is an expenditure for a country's economy as a whole as well as its health systems. Metal oxide nanoparticles play a role in overcoming microbial resistance to antibiotics. Bacterial cellulose (BC) is a biopolymer that is friendly to the environment and has a wide range of economic uses, particularly in biomedicine. This work deals with the formulation of BC-doped titanium dioxide nanoparticles (TiO₂NPs) and polydopamine (DOP), which are presented with antimicrobial activity. Additionally, the mode of addition of the doped materials was studied using physicochemical analysis, including Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD). Moreover, the topographical study used scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The antimicrobial activity was studied and showed the efficiency of the BC/DOP/TiO₂NP composite against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa, Escherichia coli) strains. Additionally, the wound healing was examined on rats that had been purposely wounded. The results observed that the mode of addition contributed to the molecular structure of the formulated BC-doped samples according to the physicochemical and topographical analysis. Moreover, the BC/DOP/TiO₂NP composite enhanced wound healing for about 95% closure by Day 14 compared to 50% in the control group. Based on the results, we can suggest BC/DOP/TiO₂NP as an excellent candidate for wound dressings.

In this study, an efficient method to prepare antibacterial hydrogel from natural resources was carried out. The extraction of mangosteen rind was made. Silver nanoparticle was introduced to the hydrogel through the reduction of AgNO₃ with the mangosteen rind extract. Hydrogels were prepared through graft-copolymerization of acrylic acid on cellulose in the presence of ammonium persulfate as initiator, followed by crosslinking with N,N′-methylenebisacrylamide. The characterization of components, structure, and properties of the rind extract and the hydrogels was carried out. The solvent mixture of water:ethanol 1:2 (v/v) was the most suitable solvent for the extraction of mangosteen rind. The silver nanoparticle was found to form a strong interaction with the composition of the hydrogel, which resulted in the improvement of the thermal property and the sterilization of both gram-positive and gram-negative bacteria. When the silver content was 9.7 ± 0.2 wt%, the hydrogel achieved the highest thermal property and antibacterial activity.