Polysaccharide Chitosan Research Articles

MMP-2 Responsive Gold Nanorods Loaded with HSP-70 siRNA for Enhanced Photothermal Tumor Therapy.

Gold nanorods (Au NRs) are a valuable photothermal nanomaterial for tumor therapy. However, when treated with Au NRs for photothermal therapy, the expression of heat shock proteins in tumors will increase, which will induce heat resistance in tumor cells and reduce the photothermal therapeutic effect of Au NRs. By RNA interference, the expression of heat shock proteins would be effectively inhibited to improve the efficasy of tumor photothermal therapy. However, deep and noninvasive tissue penetration remains a great obstacle to applying siRNA successfully. Thus, the nanoplatform AGC/HSP-70 siRNA was designed for enhanced photothermal tumor therapy by RNA interference. In the AGC/HSP-70 siRNA complex, the Au-S bond modified the matrix metalloproteinase-2 (MMP-2)-sensitive peptide GPLGLAG on the surface of gold nanorods. Moreover, the natural basic polysaccharide (chitosan) was reacted with the peptide by an amide bond for delivering heat shock protein 70 silencing siRNA (HSP-70 siRNA). Modifying the MMP-2-sensitive linker could cause more Au NRs to accumulate in tumors to exert a photothermal effect and promote the penetration of HSP-70 siRNA and chitosan complexes into deep tumor tissues. In vitro experiments indicated that the enzymolysis of the MMP-2-sensitive linker for AGC/HSP-70 siRNA could promote the cellular uptake and perinuclear distribution of HSP-70 siRNA in tumor cells, which may be due to the smaller size and positive electricity of the complexes. All of these results ensured the efficient gene silencing effect of HSP-70 siRNA to enhance the photothermal therapeutic effect of Au NRs in tumor tissues, as demonstrated by the gene silencing and cellular apoptotic experiments. In vivo experiments further proved that the AGC/HSP-70 siRNA nanoplatform efficiently improved the photothermal effect of Au NRs. In summary, this work proved that AGC/HSP-70 siRNA is a promising drug delivery strategy for enhancing the photothermal therapy of tumors by regulating the photothermal sensitivity of deep tumor cells as well as retaining more Au NRs in tumor tissues, and also provides a novel strategy for tumor photothermal therapy.

Preparation and characterization of functional dual network hydrogel for motion monitoring in smart bra

The smart bra is a kind of sports underwear with providing health monitoring and comfort protection for women breast in sports. Developing smart sensing materials that combine comfort and functionality for sensing breast condition remains a challenge. Here, natural polysaccharide sodium alginate (SA), acrylamide (AM) monomer and chitosan (CS) and polypyrrole (PPy) in-situ polymerized from pyrole (Py) monomer were used as raw materials to successfully synthesize double network conductive hydrogel by two-step method. The results show that in the hydrogels, the entanglement and interpenetration of macromolecules produce toughness (tensile/compressive strength is ∼0.248 MPa/∼2.836 MPa), elasticity (tensile/compression elastic recovery rate is∼94.06 %/∼98.41 %) and durability (after 30 tensile/compression cycles conducting at 25 %, 50 % and 100 % constant strain keep at high recovery rate). The rich moisture content provides its adhesion (adhesion strength ∼4.7557 kPa) and flexibility (bending stiffness 1.0843 cN cm∼), presenting sufficient adhesion reliability and robustness to different substrates. The addition of PPy enables the hydrogel to have conductivity (6.77 × 10−2 S cm−1) and sensing performance (tensile/compression sensitivity is ∼1.94/∼1.43). The conductive hydrogel, as a flexible strain sensor, shows good adhesion, flexibility, elasticity and sensitivity in application of sports smart bra, can detect both the tensile behavior of skin and the compression state of tissue through its mechano-electricity, and accurately sense the changes of physiological parameters during movement. The conductive hydrogel with high elasticity and strength has broad application prospects in smart bra.

Spontaneous Fusion of Core-Shell Nanocapsules with Oil Cores and Oppositely Charged Polysaccharide Shells.

Polymer nanocapsules with hydrophobic cores are promising candidates for nanoreactors to carry out (bio)chemical reactions mimicking the performance of natural cellular systems. Their architecture allows reagents to be encapsulated in the cores enabling reactions to proceed in confined environments in a controlled, and efficient manner. Polysaccharide-shell oil-core nanocapsules are proposed here as facile mergeable nanoreactors. Spontaneous fusion of oppositely charged polysaccharide capsules is demonstrated for the first time. Such capsules are formed and easily loaded with reagents by nanoemulsification of an aqueous solution of hydrophobically modified polysaccharides (chitosan, hyaluronate) and oleic acid with dissolved desired hydrophobic compounds. Efficient fusion of the formed nanocapsules dispersed in an aqueous medium at optimized conditions (pH, ionic strength) is followed using fluorescence microscopy by labeling both their cores and shells with fluorescent dyes. As a proof of concept, a model fluorogenic synthesis is also realized by fusing the capsules containing separated reagents and the catalyst. The nanocapsules and fusion process developed here establish a platform for realization of versatile reactions in a confined environment including model studies on biologically relevant processes taking place in natural systems.

Smart sensing property of Eu3+-induced polyelectrolyte nanoaggregates on nitrofuran antibiotics in aqueous environments

Pollution of water with antibiotics is a very serious global issue. So, simple, fast, and ecofriendly detection of such pollutants in aqueous environments has aroused great attention. Several intriguing properties such as narrow emission band, large stokes shift, long luminescence decay time and resistance to photobleaching distinguishes europium-based materials from commonly used fluorophores in biology as a superior optical smart material for applications in diverse fields. Herein, strongly luminescent Eu3+-induced polyelectrolyte nanoaggregates (EINAP) were synthesized and successfully characterized. The biocompatible polysaccharides hyaluronic acid and chitosan are used to disperse organic europium complexes resulting in formation of hybrid nanoaggregates. As synthesized EINAP demonstrated excellent quantum yield (89.29 %) and luminescence lifetime (656 µs). The EINAP also have high sensitivity and low limit of detection with good analytical precision for nitrofuran antibiotics in aqueous environments. The luminescent nano sensor developed in this work could be a novel tool for assessment of antibiotic pollution in the environment. The overall sensing mechanisms for detection of nitrofurans in aqueous environments were found to be the combination of inner filter effect and photoinduced electron transfer respectively.

The trajectory of vesicular proteomic signatures from HBV-HCC by chitosan-magnetic bead-based separation and DIA-proteomic analysis.

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer often associated with chronic hepatitis B virus infection (CHB) and liver cirrhosis (LC), underscoring the critical need for biomarker discovery to improve patient outcomes. Emerging as a promising avenue for biomarker development, proteomic technology leveraging liquid biopsy from small extracellular vesicles (sEV) offers new insights. Here, we evaluated various methods for sEV isolation and identified polysaccharide chitosan (CS) as an optimal approach. Subsequently, we employed optimized CS-based magnetic beads (Mag-CS) for sEV separation from serum samples of healthy controls, CHB, LC, and HBV-HCC patients. Leveraging data-independent acquisition mass spectrometry coupled with machine learning, we uncovered potential vesicular protein biomarker signatures (KNG1, F11, KLKB1, CAPNS1, CDH1, CPN2, NME2) capable of distinguishing HBV-HCC from CHB, LC, and non-HCC conditions. Collectively, our findings highlight the utility of Mag-CS-based sEV isolation for identifying early detection biomarkers in HBV-HCC.

Unravelling the tissue regenerative nature of marine polysaccharide chitosan embedded halloysite reinforced poly (vinyl alcohol) nanocomposite films

The study focuses on developing the poly (vinyl alcohol) (PVA) nanocomposite films reinforced with Halloysite Nano-Tubes (HNT) which were surface functionalised with chitosan forming a Schiff base structure. The work was aimed to traverse its way in tissue engineering. Modification of halloysite with sea polysaccharide chitosan enhanced its ability to bind to the PVA matrix. The modification was assisted by FTIR, XRD, FESEM, TEM, AFM and DSC-TGA techniques. The films could withstand a higher temperature and exhibited high ranges of tensile strength and Young’s modulus. In addition, biocompatible studies such as in-vitro swelling, enzymatic degradation, water contact angle and hemolysis presented extremely well compatibilities proving it to be viable in physiological pH (in phosphate buffered saline). The cell adhesion and proliferation studies conducted on NIH3T3 mouse fibroblasts revealed the cell proliferation and tissue regeneration properties of the films. Both the tests performed for cell growth- Trypan blue dye exclusion and Acridine Orange Ethidium bromide assays showed a doubled rate of cell growth on the films which proves its biomedical nature.Graphical

Synthesis, characterization and biocompatibility of hybrid hydrogels based on alginate, κ-carrageenan, and chitosan filled with montmorillonite clay

New hybrid hydrogel composites based on a mixture of natural polysaccharides (sodium alginate, κ-carrageenan, and chitosan) filled with the clay mineral of natural origin, montmorillonite (MMT), were studied. The structure of intercalated/flocculated MMT distribution in the interpenetrating network of polysaccharide matrix was characterized using FTIR, X-ray diffraction, and SEM techniques. Swelling kinetics was investigated using the weight analysis, whereas the phase transition of water in the composition of hybrid hydrogels, by DSC method. Their biosafety was estimated using the Nelyubov method, germination test on cress (L. sativum) seeds, and metabolic fingerprinting of microbial communities and dehydrogenase assay. The obtained results indicated promising water-retaining properties of the synthesized materials. The hydrogels had a good sorption affinity for cadmium (Cd) ions confining bioavailability of the selected toxic heavy metal. They were safe for soil microorganisms and did not generate metabolic stress for them. Moreover, they did not reduce the viability of pea seeds. Thus, the development of biosafe hybrid hydrogel composites with a comprehensive, good effect on the environment could be considered as successful.

Construction of CS-SDAEM long-chain polysaccharide derivative on TA@CNTs coated PVDF membrane with effective oil-water emulsion purification and low contamination rate

Currently, the most effective way to improve the anti-fouling performance of water treatment separation membrane is to enhance the hydrophilicity of the membrane surface, but it can still cause contamination, leading to the occurrence of flux reduction. The construction of a strong hydration layer to resist wastewater contamination is still a challenging task. In this study, a defect-free hydration layer barrier was achieved by grafting chitosan polysaccharide derivatives (CS-SDAEM) on the membrane, which achieved in effective fouling prevention and low flux decline rate. A layer of tannic acid-coated carbon nanotubes (TA@CNTs) has been uniformly deposited on the commercial PVDF membrane so that the surface was rich in -COOH groups, providing sufficient reaction sites. These reactive groups facilitate the grafting of amphiphilic polymers onto the membrane. This modification strategy achieved in enhancing the antifouling performance. The modified membrane achieved low contamination rate with DR of 16.9 % for wastewater filtration, and the flux recovery rate was above 95 % with PWF of 1100 (L·m−2·h−1). The membrane had excellent anti-fouling performance, which provided a new route for the future development of water treatment membrane.

Preparation and evaluation of gastrodin microsphere-loaded Gastrodia elata polysaccharides composite hydrogel on UVB-induced skin damage in vitro and in vivo

Skin damage from sun exposure is a common issue among outdoor workers and is primarily caused by ultraviolet rays. Upon absorption of these rays, the skin will experience inflammation and cell apoptosis. This study explored the concept of 'Combination of medicine and adjuvant' by utilizing Gastrodia elata polysaccharide, a key component of Gastrodia elata Bl.‌, to develop a new hydrogel material. Oxidized Gastrodia elata polysaccharide (OGEP) and carboxymethyl chitosan (CMCS) was use to prepare a biocompatible, biodegradable and self-healing hydrogel OGEP/CMCS (OC). And this hydrogel was further loaded with Gastrodin-containing microspheres (GAS/GEL) to create GAS/GEL/OGEP/CMCS (GGOC) hydrogel. Characterization studies revealed that OC and GGOC hydrogels exhibited favorable mechanical properties, antioxidant activity and biocompatibility. The experiments showed that OC and GGOC hydrogels could regulate mitochondrial membrane potential, prevent mitochondrial breakage, inhibit proinflammatory factors, prevent NF-κB protein activation and regulate apoptosis-related pathways. This study highlighted the application potential of Gastrodia elata polysaccharide as a ‘Combination of medicine and adjuvant’ and the anti-UVB damage effect of the prepared hydrogel.

Combining Gut Microbiota Modulation and Enzymatic-Triggered Colonic Delivery by Prebiotic Nanoparticles Improves Mouse Colitis Therapy.

The efficacy of ulcerative colitis (UC) therapy is closely connected to the composition of gut microbiota in the gastrointestinal tract. Prebiotic-based nanoparticles (NPs) provide a more precise approach to alleviate UC via modulating gut microbiota dysbiosis. The present study develops an efficient prebiotic-based colon-targeted drug delivery system (PCDDS) by using prebiotic pectin (Pcn) and chitosan (Csn) polysaccharides as a prebiotic shell, with the anti-inflammatory drug sulfasalazine (SAS) loaded into a poly(lactic-co-glycolic acid) (PLGA) core to construct SAS@PLGA-Csn-Pcn NPs. Then, we examine its characterization, cellular uptake, and invivo therapeutic efficacy. The results of our study indicate that the Pcn/Csn shell confers efficient pH-sensitivity properties. The gut microbiota-secreted pectinase serves as the trigger agent for Pcn/Csn shell degradation, and the resulting Pcn oligosaccharides possess a substantial prebiotic property. Meanwhile, the formed PCDDSs exhibit robust biodistribution and accumulation in the colon tissue, rapid cellular uptake, efficient invivo therapeutic efficacy, and modulation of gut microbiota dysbiosis in a mouse colitis model. Collectively, our synthetic PCDDSs demonstrate a promising and synergistic strategy for UC therapy.

How the Chemical Properties of Polysaccharides Make It Possible to Design Various Types of Organic-Inorganic Composites for Catalytic Applications.

Recently, the use of plant-origin materials has become especially important due to the aggravation of environmental problems and the shortage and high cost of synthetic materials. One of the potential candidates among natural organic compounds is polysaccharides, characterized by a number of advantages over synthetic polymers. In recent years, natural polysaccharides have been used to design composite catalysts for various organic syntheses. This review is devoted to the current state of application of polysaccharides (chitosan, starch, pectin, cellulose, and hydroxyethylcellulose) and composites based on their catalysis. The article is divided into four main sections based on the type of polysaccharide: (1) chitosan-based nanocomposites; (2) pectin-based nanocomposites; (3) cellulose (hydroxyethylcellulose)-based nanocomposites; and (4) starch-based nanocomposites. Each section describes and summarizes recent studies on the preparation and application of polysaccharide-containing composites in various chemical transformations. It is shown that by modifying polysaccharides, polymers with special properties can be obtained, thus expanding the range of biocomposites for catalytic applications.

Improvement effect of different polysaccharides on the functional properties of curcumin-loaded rice protein hydrolysate nanoparticles

The impact of different polysaccharides (chitosan, pectin, and chondroitin sulfate) on the functional properties of curcumin-loaded rice protein hydrolysates (RPH) was explored. Polysaccharides provided more surface charges for RPH nanoparticles, and enhanced the hydrogen bonds and electrostatic interactions between nanoparticles, thus contributing to the stability of RPH nanoparticles against environmental changes. Notably, RPH nanoparticles coated with chitosan have the largest surface charge (+33.04 mV) and best pH, ionic strength, and thermal stability. Furthermore, RPH nanoparticles coated with chondroitin sulfate had a more compact spherical structure with smaller particle size (111.23 nm), and possessed desirable sustained release properties. This study demonstrated the potential of polysaccharides to enhance the functional properties of rice protein-derived delivery systems for hydrophobic biomolecules, and suggested the necessity of polysaccharide type for creating ideal protein-polysaccharide composite nanoparticles.

Biopolymer-Based Nanomedicine for Cancer Therapy: Opportunities and Challenges.

Cancer, as the foremost challenge among human diseases, has plagued medical professionals for many years. While there have been numerous treatment approaches in clinical practice, they often cause additional harm to patients. The emergence of nanotechnology has brought new directions for cancer treatment, which can deliver anticancer drugs specifically to tumor areas. This article first introduces the application scenarios of nanotherapies and treatment strategies of nanomedicine. Then, the noteworthy characteristics exhibited by biopolymer materials were described, which make biopolymers stand out in polymeric nanomedicine delivery. Next, we focus on summarizing the state-of-art studies of five categories of proteins (Albumin, Gelatin, Silk fibroin, Zein, Ferritin), nine varieties of polysaccharides (Chitosan, Starch, Hyaluronic acid, Dextran, cellulose, Fucoidan, Carrageenan, Lignin, Pectin) and liposomes in the field of anticancer drug delivery. Finally, we also provide a summary of the advantages and limitations of these biopolymers, discuss the prevailing impediments to their application, and discuss in detail the prospective research directions. This review not only helps readers understand the current development status of nano anticancer drug delivery systems based on biopolymers, but also is helpful for readers to understand the properties of various biopolymers and find suitable solutions in this field through comparative reading.

Gelatin-Based Scaffolds with Carrageenan and Chitosan for Soft Tissue Regeneration.

Motivated by the enormous potential of hydrogels in regenerative medicine, new biocompatible gelatin-based hybrid hydrogels were developed through a green process using poly(ethylene glycol) diglycidyl ether as a cross-linking agent, adding carrageenan and chitosan polysaccharides to the network to better mimic the hybrid composition of native extracellular matrix. Overall, the hydrogels show suitable structural stability, high porosity and pore interconnectivity, good swellability, and finally, biocompatibility. Their mechanical behavior, investigated by tensile and compression tests, appears to be characterized by nonlinear elasticity with high compliance values, fast stress-relaxation, and good strain reversibility with no sign of mechanical failure for compressive loading-unloading cycles at relatively high deformation levels of 50%. Degradation tests confirm the hydrogel bioresorbability by gradual hydrolysis, during which the structural integrity of both materials is maintained, while their mechanical behavior becomes more and more compliant. Human Umbilical Cord-derived Mesenchymal Stem Cells (hUC-MSCs) were used to test the hydrogels as potential carriers for cell delivery in tissue engineering. hUC-MSCs cultured inside the hydrogels show a homogenous distribution and maintain their growth and viability for at least 21 days of culture, with an increasing proliferation trend. Hence, this study contributes to a further understanding of the potential use of hybrid hydrogels and hUC-MSCs for a wide range of biomedical applications, particularly in soft tissue engineering.

Isolation and Free Radical Scavenging Ability of Linear Polysaccharides From Cuttlebone of Sepia prashadi.

Background This study aimed to isolate linear polysaccharides from Sepia prashadi cuttlebone with the objective of evaluating their ability to scavenge free radicals. By providing new natural components for pharmaceutical and functional food uses, this research advances our understanding of the potential health benefits of polysaccharides originating from marine sources and their antioxidant properties. Objective The objective of the study is to isolate a linear polysaccharide chitosan from Sepia prashadi cuttlebone(produced by the partial deacetylation of chitin),characterize its structure using fourier transform infrared spectroscopy (FTIR),scanning electron microscopy (SEM), and X-ray diffraction (XRD), and explore the isolated polysaccharide's free radical scavenging potential. Material and methods Linear polysaccharide, chitosan was extracted chemically from Sepia prashadifrom cuttlebone waste, by demineralization and deproteinization.Chemical characterization of chitosan was performed using Fourier transform infrared spectroscopy (FTIR) in the 400-4000 nm frequency range. The surface characteristics of chitosan, such as its texture, porosity, and roughness, are visible in scanning electron microscopy (SEM) images. X-ray diffraction (XRD) canbe utilized to examine how chitosan interacts with other substances, such as medications or nanoparticles, by analyzing alterations in thediffraction pattern during complexation or formulation. Scavenging ability was demonstrated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide radical, and chelating ability of ferrous ions assays. Results Chitosan is formed from chitin. The extraction yields of chitosan and chitin were 78% and 39%, respectively. High levels of superoxide radical scavenging activity (76.1%), DPPH radical scavenging activity (62.1%) and chelating activity (127.5% at 100 g/mL) were observed in cuttlebone chitosan. Sepia prashadi showed an increased antioxidant activity in chitosan. Conclusion The goal of this study was to determine the effectiveness of various extraction techniques for preserving the antioxidant activity of chitosan derived from Sepia prashadicuttlebone waste. The maximum scavenging activity was demonstrated by both the chelating ability and antioxidant activity. Considering that this raw material is derived from renewable resources and produces highly valued chemicals, it is a profitable endeavor.

A Zn/Cd/Ni Metal-Organic Framework-Based Solid and Flexible Fluoroprobes for Highly Selective Detection of 4-Nitroaniline in Real Water Samples.

The combination of diazabicyclic compound i.e. 1,4-diazabicyclo[2.2.2]octane (DABCO) and dicarboxylate linker 1,4-dicarboxylic acid are employed to self-assemble with three divalent metal ions such as Zn2+, Cd2+, Ni2+ led to the formation of highly stable pillar layered luminescent metal-organic frameworks. The emissive response of as-synthesized MOFs was studied in organic solvents with different functionalities resulting in the development of fluoroprobes having excellent recognition ability for 4-nitroaniline with detection limit upto micromolar. All the MOFs display a good linear relation between the fluorescence intensity and concentration of 4-NA in the range of 10-90µmol L-1. The values of Ksv for Zn-MOF, Cd-MOF, and Ni-MOF are found to be 1.75 × 104mol-1L, 1.25 × 104mol-1L, and 28.0 × 104mol-1L, respectively. The calculated detection limit values are 19.7µmol L-1, 27.6µmol L-1, and 1.19µmol L-1 respectively. Moreover, the study was further extended to fabricate the solid membrane-based fluoroprobe using a linear chitosan polysaccharide and act as an efficient solid fluoroprobe for the detection of 4-NA. This proposed synthesis of polymeric membrane facilitates the MOF@chitosan fluorophore to transfer its fluorescence-emissive nature to a solid state.

Biopolymer-derived structured graphitic carbons as metal-free heterogeneous ozonation catalysts in water

The development of metal-free heterogeneous catalysts for advanced oxidation processes is an important area of research, advancing in sustainability, with potential practical applications in water treatment. In this work, we report the development of defective structured graphitic carbons synthesized from biomass including alginate or chitosan polysaccharides and used as metal-free ozonation catalysts in water. These solids were characterized by several techniques, including powder X-ray diffraction, several spectroscopies (i.e. X-ray photoelectron, Raman or Fourier Transform infrared), elemental combustion analyses, thermogravimetric measurements, and electron microscopic techniques. The catalytic performance of graphitic carbon was examined in the ozonation reaction and the graphitic carbon derived from alginate (G) was found to be the most active catalyst by showing complete degradation in less than 4 h under the operational conditions as oxalic acid (50 mg L−1), catalyst (100 mg L−1), 20 °C, O3 dosage (140 mg h−1) at pH 3. Importantly, this solid retains its activity mostly upon reuse for more than 20 h, an observation that compares favorably with previous reports using graphene-based materials. In addition, activity of partially deactivated catalyst can be recovered by a pyrolysis process associated to the reconstitution of graphitic active sites of the catalyst. Experimental evidence by electron spin resonance together with specific (photo)catalytic experiments is provided to support the role of 1O2 as key intermediate during the oxalic acid degradation in water in the presence of G. This study exemplifies the activity of active graphitic-based solids from biomass precursors as ozonation heterogeneous catalysts in water in the absence of any metal.

Synthesis of Thermoresponsive Chitosan-graft-Poly(N-isopropylacrylamide) Hybrid Copolymer and Its Complexation with DNA.

A hybrid synthetic-natural, thermoresponsive graft copolymer composed of poly(N-isopropyl acrylamide) (PNIPAM) side chains, prepared via RAFT polymerization, and a chitosan (Chit) polysaccharide backbone, was synthesized via radical addition-fragmentation reactions using the "grafting to" technique, in aqueous solution. ATR-FTIR, TGA, polyelectrolyte titrations and 1H NMR spectroscopy were employed in order to validate the Chit-g-PNIPAM copolymer chemical structure. Additionally, 1H NMR spectra and back conductometric titration were utilized to quantify the content of grafted PNIPAM side chains. The resulting graft copolymer contains dual functionality, namely both pH responsive free amino groups, with electrostatic complexation/coordination properties, and thermoresponsive PNIPAM side chains. Particle size measurements via dynamic light scattering (DLS) were used to study the thermoresponsive behavior of the Chit-g-PNIPAM copolymer. Thermal properties examined by TGA showed that, by the grafting modification with PNIPAM, the Chit structure became more thermally stable. The lower critical solution temperature (LCST) of the copolymer solution was determined by DLS measurements at 25-45 °C. Furthermore, dynamic and electrophoretic light scattering measurements demonstrated that the Chit-g-PNIPAM thermoresponsive copolymer is suitable of binding DNA molecules and forms nanosized polyplexes at different amino to phosphate groups ratios, with potential application as gene delivery systems.

Bletilla striata Polysaccharide-/Chitosan-Based Self-Healing Hydrogel with Enhanced Photothermal Effect for Rapid Healing of Diabetic Infected Wounds via the Regulation of Microenvironment.

The management of diabetic ulcers poses a significant challenge worldwide, and persistent hyperglycemia makes patients susceptible to bacterial infections. Unfortunately, the overuse of antibiotics may lead to drug resistance and prolonged infections, contributing to chronic inflammation and hindering the healing process. To address these issues, a photothermal therapy technique was incorporated in the preparation of wound dressings. This innovative solution involved the formulation of a self-healing and injectable hydrogel matrix based on the Schiff base structure formed between the oxidized Bletilla striata polysaccharide (BSP) and hydroxypropyltrimethylammonium chloride chitosan. Furthermore, the introduction of CuO nanoparticles encapsulated in polydopamine imparted excellent photothermal properties to the hydrogel, which promoted the release of berberine (BER) loaded on the nanoparticles and boosted the antibacterial performance. In addition to providing a reliable physical protection to the wound, the developed hydrogel, which integrated the herbal components of BSP and BER, effectively accelerated wound closure via microenvironment regulation, including alleviated inflammatory reaction, stimulated re-epithelialization, and reduced oxidative stress based on the promising results from cell and animal experiments. These impressive outcomes highlighted their clinical potential in safeguarding the wound against bacterial intrusion and managing diabetic ulcers.

Modulation of mesalamine release from enteric-coated matrix tablets using natural polysaccharides for localized colonic delivery

Background: Inflammatory bowel diseases (IBD) require effective colon-targeted drug delivery for improved therapeutic efficacy and minimized systemic side effects. Objectives: The objective of this research was to develop and evaluate novel colon-targeted matrix tablet formulations of mesalamine (5-aminosalicylic acid) for the treatment of IBD. Materials and Methods: Mesalamine matrix tablets were prepared by wet granulation technique using pH-sensitive polymers (HPMC K4M) and biodegradable natural polysaccharides (pectin, chitosan, and guar gum). Tablets were characterized for physicochemical properties, drug content, and in vitro drug release. Compatibility studies using FTIR and DSC confirmed no interaction between mesalamine and polymers. The optimized formulations were enteric-coated with Eudragit S100 and ethyl cellulose. Drug release kinetics and stability studies were conducted. Results and Discussion: The uncoated formulations (M3, M6, M7) showed adequate protection against drug release in simulated gastric (0-2 h) and intestinal (2-5 h) fluids. The enteric-coated formulations (ME3, ME6, ME7) exhibited a lag time of around 2 hours and restricted drug release (<5%) in simulated gastric and intestinal fluids up to 5 hours. However, in simulated colonic fluid (pH 6.8) containing 4% rat cecal contents, these formulations showed enhanced drug release (71-83% in 12 h) due to biodegradation of polymeric matrices by colonic enzymes. Drug release kinetics indicated anomalous transport or super case-II transport mechanisms. Stability studies at 40°C/75% RH for 3 months revealed no significant changes. Conclusion: The developed colon-targeted mesalamine matrix tablets demonstrated the potential to protect the drug from release in the upper GIT while facilitating targeted drug delivery to the colon, which could improve therapeutic efficacy and minimize systemic side effects in the treatment of IBD.