Effects of hydroxybutyl chitosan on improving immunocompetence and antibacterial activities

Effect of a Thermosensitive Hydroxybutyl Chitosan Hydrogel on Postoperative Sequalae and Quality of Life After Impacted Mandibular Third Molar Extraction

BACKGROUND

Third molar (M3) extraction is a common surgery in oral and maxillofacial surgery, and composite wound dressings such as hydroxybutyl chitosan (HBC) may improve postoperative sequala following M3 removal.

PURPOSE

The study purpose was to measure and compare differences in pain, swelling, trismus, wound healing, and quality of life (QOL) between the HBC and the control sides in patients undergoing M3 removal.

STUDY DESIGN, SETTING, SAMPLE

This study is a double-blind, split-mouth, randomized clinical trial. Patients who required M3 removal between June 2022 and May 2023 were included. Exclusion criteria included seafood allergies, smoking, poor oral hygiene, and systemic diseases.

PREDICTOR VARIABLE

The predictor variable was the socket treatment technique. Subjects were randomly assigned to the HBC or control (physiological saline) side.

MAIN OUTCOME VARIABLE

The primary outcome variables, including pain assessed by visual analog scale, swelling, and maximal incisional opening, were measured on the first, third, and seventh postoperative days. The secondary outcome variables included QOL and wound healing score measured on the third and seventh days after surgery.

COVARIATES

The covariates included age, sex, and operation time.

ANALYSES

The Shapiro‒Wilk test was used to evaluate the normality of the data distribution. The paired t test or Wilcoxon signed-rank test was adopted. Statistical significance was set at P < .05.

RESULTS

The study included 60 patients (mean age: 25.81 ± 4.91; 23 (38%) males, 37 (62%) females). A statistically significant difference in the level of pain (HBC: 37.58 ± 4.39 mm, control: 47.00 ± 4.33 mm, day 1, P < .001; 21.88 ± 3.25 mm, 35.95 ± 1.57 mm, day 3, P < .001), maximal incisional opening (23.92 ± 1.38 mm, 18.22 ± 1.82 mm, day 1, P < .001; 30.00 ± 1.61 mm, 23.78 ± 1.70 mm, day 3, P < .001), and swelling (6.86 ± 0.70 mm, 7.15 ± 0.80 mm, day 3, P = .006) was detected after surgery. A statistically significant difference in QOL was detected (HBC: 13.70 ± 1.65, control: 18.60 ± 2.14, day 3, P < .001).

CONCLUSION AND RELEVANCE

The application of HBC hydrogels to wounds after impacted mandibular M3 extraction reduces postoperative sequalae, promotes wound healing and improves postoperative QOL.

Polydopamine-Coated Copper-Doped Co3O4 Nanosheets Rich in Oxygen Vacancy on Titanium and Multimodal Synergistic Antibacterial Study

Medical titanium-based (Ti-based) implants in the human body are prone to infection by pathogenic bacteria, leading to implantation failure. Constructing antibacterial nanocoatings on Ti-based implants is one of the most effective strategies to solve bacterial contamination. However, single antibacterial function was not sufficient to efficiently kill bacteria, and it is necessary to develop multifunctional antibacterial methods. This study modifies medical Ti foils with Cu-doped Co3O4 rich in oxygen vacancies, and improves their biocompatibility by polydopamine (PDA/Cu-Ov-Co3O4). Under near-infrared (NIR) irradiation, nanocoatings can generate •OH and 1O2 due to Cu+ Fenton-like activity and a photodynamic effect of Cu-Ov-Co3O4, and the total reactive oxygen species (ROS) content inside bacteria significantly increases, causing oxidative stress of bacteria. Further experiments prove that the photothermal process enhances the bacterial membrane permeability, allowing the invasion of ROS and metal ions, as well as the protein leakage. Moreover, PDA/Cu-Ov-Co3O4 can downregulate ATP levels and further reduce bacterial metabolic activity after irradiation. This coating exhibits sterilization ability against both Escherichia coli and Staphylococcus aureus with an antibacterial rate of ca. 100%, significantly higher than that of bare medical Ti foils (ca. 0%). Therefore, multifunctional synergistic antibacterial nanocoating will be a promising strategy for preventing bacterial contamination on medical Ti-based implants.

Preparation and sustained-release mechanism of hydroxybutyl chitosan/graphene oxide temperature-sensitive hypoglycaemic subcutaneous implants

The current situation of diabetes prevention and control is extremely severe. For instance, glimepiride (GLM), a third-generation sulfonylurea, demonstrates suboptimal clinical efficacy in oral dosage forms, which underscores the pressing need for the development of a new dosage form. Recently, in situ gel subcutaneous implants have garnered considerable attention. Hydroxybutyl chitosan (HBC) can spontaneously crosslink to form a thermosensitive hydrogel and has good biocompatibility. However, its application is hindered by its limited mechanical properties. Graphene oxide (GO), known for its stable dispersion in water, can load GLM through π-π stacking interactions. When combined with HBC, GO enhances the mechanical properties and stability of the hydrogel. Therefore, an HBC-GO@GLM hydrogel was prepared. Rheological analysis revealed that the incorporation of GO increased the critical gelation temperature of the 5 wt% HBC hydrogel from 19.1°C to 27.2°C, considerably enhancing the mechanical properties of the hydrogel. Using encapsulation efficiency as an evaluation index, the optimal encapsulation efficiency of GO@GLM was determined to be 73.53% ± 0.45% with a drug loading capacity of 27.39 ± 0.17% using the Box-Behnken design model. Computer simulation technology validated the interaction between the materials and the drug release mechanism. Pharmacokinetic results showed that compared to the HBC@GLM group, the half-life (t1/2), mean residence time and the area under the curve for the HBC-GO@GLM group were approximately 3 times those of the HBC@GLM group. Subcutaneous implantation of the HBC-GO@GLM hydrogel for drug delivery considerably extended the drug's action time in the body, thereby maintaining blood sugar levels within a normal and stable range for an extended period.

Zinc-mineralized diatom biosilica/hydroxybutyl chitosan composite hydrogel for diabetic chronic wound healing

For sustained and stable improvement of the diabetic wound microenvironment, a temperature-sensitive composite hydrogel (ZnDBs/HBC) composed of inorganic zinc mineralized diatom biosilica (ZnDBs) and hydroxybutyl chitosan (HBC) was developed. The interfacial anchoring effect between ZnDBs and HBC enhanced the mechanical strength of the hydrogel. The mechanical strength of the composite hydrogel containing 3 wt% ZnDBs was increased by nearly 2.3times. The hydrogel can be used as a carrier for sustained release of Zn2+ for at least 72 h. In diabetic rats models, ZnDBs/HBC composite hydrogel could accelerate the inflammatory process by regulating the expression of pro-inflammatory factor IL-6 and anti-inflammatory factor IL-10, and also promote tissue cell proliferation and collagen deposition, thereby restoring the normal healing process and accelerating wound healing. The wound contraction rate of the composite hydrogel group was more than 2 times that of the control group. Therefore, ZnDBs/HBC composite hydrogel has the potential to be used as a therapeutic dressing for diabetic chronic wounds.

Antimicrobial photodynamic therapy for the treatment of oral infections: A systematic review

Oral infection is a common clinical symptom. While antibiotics are widely employed as the primary treatment for oral diseases, the emergence of drug-resistant bacteria has necessitated the exploration of alternative therapeutic approaches. One such modality is antimicrobial photodynamic therapy (aPDT), which utilizes light and photosensitizers. Indeed, aPDT has been used alone or in combination with other treatment options dealing with periodontal disease for the elimination of biofilms from bacterial community to achieve bone formation and/or tissue regeneration. In this review article, in addition to factors affecting the efficacy of aPDT, various photosensitizers, the latest technology and perspectives on aPDT are discussed in detail. More importantly, the article emphasizes the novel design and clinical applications of photosensitizers, as well as the synergistic effects of chemical and biomolecules with aPDT to achieve the complete eradication of biofilms and even enhance the biological performance of tissues surrounding the treated oral area.

Thermoreversible and tunable supramolecular hydrogels based on chitosan and metal cations

A new thermoreversible and tunable hydrogel CS-M with high water content prepared by metal cation (M = Cu²⁺, Zn²⁺, Cd²⁺ and Ni²⁺) and chitosan (CS) was reported. The influence of metal cations on the thermosensitive gelation of CS-M systems were studied. All prepared CS-M systems were in the transparent and stable sol state and could become the gel state at gelation temperature (T_g). These systems after gelation could recover to its original sol state at low temperature. CS-Cu hydrogel was mainly investigated and characterized due to its large T_g scale (32-80 °C), appropriate pH range (4.0-4.6) and low Cu²⁺ concentration. The result showed that the T_g range was influenced and could be tuned by adjusting Cu²⁺ concentration and system pH within an appropriate range. The influence of anions (Cl^-, NO3^- and Ac^-) in cupric salts in the CS-Cu system was also investigated. Scale application as heat insulation window was investigated outdoors. The different supramolecular interactions of the -NH₂ group in chitosan at different temperatures were proposed to dominate the thermoreversible process of CS-Cu hydrogel.

Chitosan: A Potential Biopolymer in Drug Delivery and Biomedical Applications

Chitosan, a biocompatible and biodegradable polysaccharide derived from chitin, has surfaced as a material of promise for drug delivery and biomedical applications. Different chitin and chitosan extraction techniques can produce materials with unique properties, which can be further modified to enhance their bioactivities. Chitosan-based drug delivery systems have been developed for various routes of administration, including oral, ophthalmic, transdermal, nasal, and vaginal, allowing for targeted and sustained release of drugs. Additionally, chitosan has been used in numerous biomedical applications, such as bone regeneration, cartilage tissue regeneration, cardiac tissue regeneration, corneal regeneration, periodontal tissue regeneration, and wound healing. Moreover, chitosan has also been utilized in gene delivery, bioimaging, vaccination, and cosmeceutical applications. Modified chitosan derivatives have been developed to improve their biocompatibility and enhance their properties, resulting in innovative materials with promising potentials in various biomedical applications. This article summarizes the recent findings on chitosan and its application in drug delivery and biomedical science.

Chitosan-based hemostatic sponges as new generation hemostatic materials for uncontrolled bleeding emergency: Modification, composition, and applications

The choice of hemostatic technique is a curial concern for surgery and as first-aid treatment in combat. To treat uncontrolled bleeding in complex wound environments, chitosan-based hemostatic sponges have attracted significant attention in recent years because of the excellent biocompatibility, degradability, hemostasis and antibacterial properties of chitosan and their unique sponge-like morphology for high fluid absorption rate and priority aggregation of blood cells/platelets to achieve rapid hemostasis. In this review, we provide a historical perspective on the use of chitosan hemostatic sponges as the new generation of hemostatic materials for uncontrolled bleeding emergencies in complex wounds. We summarize the modification of chitosan, review the current status of preparation protocols of chitosan sponges based on various composite systems, and highlight the recent achievements on the detailed breakdown of the existing chitosan sponges to present the relationship between their composition, physical properties, and hemostatic capacity. Finally, the future opportunities and challenges of chitosan hemostatic sponges are also proposed.

Corrigendum: Applications of chitosan and its derivatives in skin and soft tissue diseases

[This corrects the article DOI: 10.3389/fbioe.2022.894667.].

Applications of Chitosan and its Derivatives in Skin and Soft Tissue Diseases

Chitosan and its derivatives are bioactive molecules that have recently been used in various fields, especially in the medical field. The antibacterial, antitumor, and immunomodulatory properties of chitosan have been extensively studied. Chitosan can be used as a drug-delivery carrier in the form of hydrogels, sponges, microspheres, nanoparticles, and thin films to treat diseases, especially those of the skin and soft tissue such as injuries and lesions of the skin, muscles, blood vessels, and nerves. Chitosan can prevent and also treat soft tissue diseases by exerting diverse biological effects such as antibacterial, antitumor, antioxidant, and tissue regeneration effects. Owing to its antitumor properties, chitosan can be used as a targeted therapy to treat soft tissue tumors. Moreover, owing to its antibacterial and antioxidant properties, chitosan can be used in the prevention and treatment of soft tissue infections. Chitosan can stop the bleeding of open wounds by promoting platelet agglutination. It can also promote the regeneration of soft tissues such as the skin, muscles, and nerves. Drug-delivery carriers containing chitosan can be used as wound dressings to promote wound healing. This review summarizes the structure and biological characteristics of chitosan and its derivatives. The recent breakthroughs and future trends of chitosan and its derivatives in therapeutic effects and drug delivery functions including anti-infection, promotion of wound healing, tissue regeneration and anticancer on soft tissue diseases are elaborated.

Quantitative analysis of degree of substitution/molar substitution of etherified polysaccharide derivatives

Due to the unique properties such as nontoxicity, biodegradability, availability from renewable resources, and cost-effectiveness, polysaccharides play a very important part in the science and technology field. The various chemically modified derivatives of these offer a wide range of high value-added in both food and non-food industries. Among the chemical modification, etherified polysaccharide is one of the most widespread derivatives by introducing an ether group which is commonly stable in both acidic and alkaline conditions. Hydroxyalkylation, alkylation, carboxymethylation, cationization, and cyanoethylation are some of the modifications commonly employed to prepare polysaccharides ethers derivatives. There also has been a growing tendency for creating new types of modification by combining the different means of chemical techniques. The correct determination of degree of substitution (DS)/molar substitution (MS) is crucially important. The objective of this article is to summarize developments in synthetic etherified polysaccharides, involving analytical methods for determination of MS/DS, measurement processes, and the associated mechanisms.

Preparation and properties of caffeic-chitosan grafting fish bone collagen peptide

In this study, a novel peptide grafted chitosan (CACS-FBP) with high peptide content, excellent moisture-absorption and moisture-retention abilities was prepared. Caffeic acid (CA) was used to modify chitosan, the highly water-soluble intermediate further reacted with fish bone collagen peptide to obtain the final product, and the synthesis of CACS-FBP was confirmed by the Fourier transform infrared spectroscopy (FT-IR), NMR, and UV-vis. The single-factor experiments indicated that the degree of substitution (DS) of CACS-FBP depended on the reaction temperature, reaction time, the mass ratio of fish bone collagen peptide to CACS (mFBP/mCACS) and the mass ratio of MTGase to CACS (mMTGase/mCACS). In addition, the antioxidant assay indicated that CACS-FBP had an excellent antioxidant capacity, and the CACS-FBP showed no cytotoxicity toward L929 mouse fibroblasts, all the results mean that the prepared peptide-containing chitosan derivative has potential application in pharmaceutical and biomedical fields.

3D bioprinted neural tissue constructs for spinal cord injury repair

Three-dimensional (3D) bioprinting has emerged as a promising approach to fabricate living neural constructs with anatomically accurate complex geometries and spatial distributions of neural stem cells (NSCs) for spinal cord injury (SCI) repair. The NSC-laden 3D bioprinting, however, still faces some big challenges, such as cumbersome printing process, poor cell viability, and minimal cell-material interaction. To address these issues, we have fabricated NSC-laden scaffolds by 3D bioprinting and explore for the first time their application for in vivo SCI repair. In our strategy, we have developed a novel biocompatible bioink consisting of functional chitosan, hyaluronic acid derivatives, and matrigel. This bioink shows fast gelation (within 20 s) and spontaneous covalent crosslinking capability, facilitating convenient one-step bioprinting of spinal cord-like constructs. Thus-fabricated scaffolds maintain high NSC viability (about 95%), and offer a benign microenvironment that facilitates cell-material interactions and neuronal differentiation for optimal formation of neural network. The in vivo experiment has further demonstrated that the bioprinted scaffolds promoted the axon regeneration and decreased glial scar deposition, leading to significant locomotor recovery of the SCI model rats, which may represent a general and versatile strategy for precise engineering of central nervous system and other neural organs/tissues for regenerative medicine application.

Eco-friendly synthesis of an alkyl chitosan derivative

Chitosan (CH) was N-alkylated via Schiff base formation and further reduced via sodium borohydride. The reaction was carried out at room temperature, in a homogeneous aqueous medium, using as a source of alkyl group an essential oil (Eucalyptus staigeriana) containing an unsaturated aldehyde (3,7-dimethylocta-2,6-dienal). Derivatives were characterized by Infrared Spectroscopy, proton and carbon Nuclear Magnetic Resonance, XRD, particle size distribution and zeta potential. Chitosan hydrophobization evidence was given by FTIR as new bands at 2929 cm^-1 due to methyl groups, along with the presence of strong band at 1580 cm^-1 owing to N substitution. Moreover, carbon and proton NMR corroborated the insertion of methyl groups in chitosan backbone. The degree of substitution was found to be in the range 0.69-1.44. X-ray diffractograms revealed that the insertion of alkyl substituents in chitosan backbone led to a less crystalline material. Data from antibacterial activity revealed that chitosan and derivatives were effective against Gram-positive bacteria, whereby derivatives exhibited greater inhibitory effect than CH. Derivatives are likely candidates for use as carriers for active principles of interest of food, pharmacy and medicine.

New Opportunity to Formulate Intranasal Vaccines and Drug Delivery Systems Based on Chitosan

In an attempt to develop drug delivery systems that bypass the blood–brain barrier (BBB) and prevent liver and intestinal degradation, it was concluded that nasal medication meets these criteria and can be used for drugs that have these drawbacks. The aim of this review is to present the influence of the properties of chitosan and its derivatives (mucoadhesion, permeability enhancement, surface tension, and zeta potential) on the development of suitable nasal drug delivery systems and on the nasal bioavailability of various active pharmaceutical ingredients. Interactions between chitosan and proteins, lipids, antigens, and other molecules lead to complexes that have their own applications or to changing characteristics of the substances involved in the bond (conformational changes, increased stability or solubility, etc.). Chitosan and its derivatives have their own actions (antibacterial, antifungal, immunostimulant, antioxidant, etc.) and can be used as such or in combination with other molecules from the same class to achieve a synergistic effect. The applicability of the properties is set out in the second part of the paper, where nasal formulations based on chitosan are described (vaccines, hydrogels, nanoparticles, nanostructured lipid carriers (NLC), powders, emulsions, etc.).

Fully bio-based coating from chitosan and phytate for fire-safety and antibacterial cotton fabrics

In this study, a fully bio-based coating was constructed by layer-by-layer deposition of chitosan (CS) and ammonium phytate (AP), to obtain fire-safety and antibacterial cotton fabrics. With about 8% weight gains of CS/AP coatings, the treated cotton fabrics self-extinguished in the vertical burning test. The data obtained from cone calorimetry showed CS/AP/cotton had much lower smoke and heat production, which indicated the fire safety of the fabrics was significantly improved for the presence of CS/AP coatings. The flame-retardant mechanism of this system was finally proposed according to the analysis of gaseous products and char residues. What is more, CS/AP coatings had higher antibacterial activity in Gram-negative bacteria and did improve the tensile strength of cotton fabrics compared with AP coating. With its ease of operation and use of non-toxic chemicals, this fully bio-based coating can further offer a feasible flame-retardant and antibacterial solution of the inflammable natural fabrics.

Preparation of 2,6-diurea-chitosan oligosaccharide derivatives for efficient antifungal and antioxidant activities

In this study, 2-urea-chitosan oligosaccharide derivatives (2-urea-COS derivatives) and 2,6-diurea-chitosan oligosaccharide derivatives (2,6-diurea-COS derivatives) were successfully designed and synthesized via intermediate 2-methoxyformylated chitosan oligosaccharide. All samples were characterized and compared based on FT-IR, ¹H NMR spectroscopy, and elemental analysis. The antifungal effects of COS derivatives were tested against Fusarium oxysporum f. sp. niveum, Phomopsis asparagus, and Botrytis cinereal. Their antioxidant properties, including superoxide radicals' scavenging activity, hydroxyl radicals' scavenging activity, and DPPH radicals' scavenging activity were also explored within different concentrations. COS derivatives bearing urea groups showed improved bioactivity compared with pristine COS and 2,6-diurea-COS derivatives had a higher biological activity than 2-urea-COS derivatives in tested concentrations. Additionally, L929 cells were used to carry out cytotoxicity test of COS and COS derivatives by CCK-8 assay. The results indicated that some of samples showed low cytotoxicity. These findings offered a suggestion that COS derivatives bearing urea groups are promising biological materials.