Capacidade terapêutica da fitoterapia na odontologia: uma análise abrangente das proteínas antimicrobianas, anti-inflamatórias e reparadoras / Therapeutic capacity of phytotherapy in dentistry: a comprehensive analysis of antimicrobial, anti-inflammatory, and reparative properties

Introdução: A fitoterapia se baseia na utilização de plantas medicinais, através de diferentes formulações farmacêuticas com fins terapêuticos. Na Odontologia, os fitoterápicos têm sido alvo de estudos, devido suas propriedades benéficas, além de apresentarem biocompatibilidade, baixo custo e fácil acesso. Objetivo: Realizar um levantamento na literatura científica sobre a utilização da fitoterapia na Odontologia, com vistas aos efeitos antimicrobiano, anti-inflamatório e reparador. Material e Métodos: A busca ocorreu entre fevereiro a julho/2023, nas bases PubMed e LILACS, além de livre busca, cruzando-se os descritores "Phytotherapy", "Dentistry", "Anti-inflamatory Agents", "Anti-Infective Agents", "Wound Healing", "Fitoterapia", "Odontologia", "Anti-inflamatório", "Antimicrobiano" e "Cicatrização". Após leitura inicial, seguida da análise crítica com aplicação dos critérios estabelecidos, foram selecionadas 50 referências. Desenvolvimento: Diversas plantas são empregadas sob a forma de fitoterapia, como Aloe vera (babosa), Matricaria recutita (camomila), Copaifera (copaíba), Punica granatum (romã), Uncaria tomentosa (unha-de-gato), Malva sylvestris (malva), Althaea officinalis (malvaísco), Myracrodruon urundeuva (Aroeira), Lippia sidoides (Alecrim pimenta) e Glycyrrhiza glabra (Alcaçuz). Na Odontologia, pesquisas evidenciaram resultados satisfatórios para o tratamento de afecções da cavidade oral, especialmente com caráter inflamatório e infeccioso, além de aclerar a cicatrização. Esses achados apontam que a fitoterapia é um tratamento eficaz, acessível e com mínimos efeitos colaterais. Considerações finais: Com base na literatura revisada, a fitoterapia parece ser uma alternativa promissora no tratamento de afecções orais, devido aos seus notáveis efeitos cicatrizantes, antimicrobianos e anti-inflamatórios. Contudo, mais pesquisas com metodologias adequadas são necessárias para que se estabeleçam protocolos clínicos seguros e eficazes.

Introduction: Phytotherapy is based on the use of medicinal plants through different pharmaceutical formulations for therapeutic purposes. In Dentistry, phytotherapeutics have been the subject of studies due to their beneficial properties, as well as their biocompatibility, low cost, and easy accessibility. Objective: To conduct a literature review on the use of phytotherapy in Dentistry, focusing on antimicrobial, anti-inflammatory, and reparative effects. Materials and Methods: The search took place between February and July 2023, using PubMed and LILACS databases, in addition to a free search, crossing the descriptors "Phytotherapy," "Dentistry," "Anti-inflammatory Agents," "Anti-Infective Agents," "Wound Healing," "Fitoterapia," "Odontologia," "Anti-inflammatory," "Antimicrobial," and "Cicatrização." After an initial reading, followed by critical analysis with the application of established criteria, 50 references were selected. Development: Various plants are employed in phytotherapy, such as Aloe vera (aloe), Matricaria recutita (chamomile), Copaifera (copaiba), Punica granatum (pomegranate), Uncaria tomentosa (cat's claw), Malva sylvestris (mallow), Althaea officinalis (marshmallow), Myracrodruon urundeuva (Brazilian copaiba), Lippia sidoides (rosemary pepper), and Glycyrrhiza glabra (licorice). In Dentistry, research has shown satisfactory results for the treatment of oral cavity conditions, especially those with inflammatory and infectious characteristics, as well as accelerating healing. These findings suggest that phytotherapy is an effective, accessible treatment with minimal side effects. Final considerations: Based on the reviewed literature, phytotherapy appears to be a promising alternative in the treatment of oral conditions due to its notable healing, antimicrobial, and anti-inflammatory effects. However, more research with appropriate methodologies is necessary to establish safe and effective clinical protocols.

Topical frankincense treatment for frostbite based on microcirculation improvements.

ETHNOPHARMACOLOGICAL RELEVANCE: The Chinese traditional medicine frankincense, which can promote blood circulation, is often used to treat skin lesions, including frostbite. AIM OF THE STUDY: To explore the properties of frankincense oil extract (FOE) and its active ingredients and their effect on frostbite wound recovery as an approach to understand the mechanism associated with microcirculation-improvement therapy. MATERIALS AND METHODS: The microcirculation-improving effects of FOE and its active ingredients were evaluated using liquid nitrogen-induced frostbite animal models. The rewarming capacity of FOE on the skin was determined through infrared detection, and frostbite wound healing was evaluated following haematoxylin and eosin (H&E) staining and fibre analysis. Moreover, related factors were examined to determine the anti-apoptotic, anti-inflammatory, and microcirculatory properties of FOE and its active ingredients on affected tissue in the context of frostbite. RESULTS: FOE and its active ingredients rapidly rewarmed wound tissue after frostbite by increasing the temperature. Moreover, these treatments improved wound healing and restored skin structure through collagen and elastin fibre remodelling. In addition, they exerted anti-apoptotic effects by decreasing the number of apoptotic cells, reducing caspase-3 expression, and eliciting anti-inflammatory effects by decreasing COX-2 and ß-catenin expression. They also improved microcirculatory disorders by decreasing HIF-1α expression and increasing CD31 expression. CONCLUSIONS: FOE and its active components can effectively treat frostbite by enhancing microcirculation, inhibiting the infiltration of inflammatory cells, decreasing cell apoptosis, and exerting antinociceptive effects. These findings highlight FOE as a new treatment option for frostbite, providing patients with an effective therapeutic strategy.

A dendritic cell-recruiting, antimicrobial blood clot hydrogel for melanoma recurrence prevention and infected wound management.

Surgical resection, the mainstay for melanoma treatment, faces challenges due to high tumor recurrence rates and complex postoperative wound healing. Chronic inflammation from residual disease and the risk of secondary infections impede healing. We introduce an innovative, injectable hydrogel system that integrates a multifaceted therapeutic approach. The hydrogel, crosslinked by calcium ions with sodium alginate, encapsulates a blood clot rich in dendritic cells (DCs) chemoattractants and melanoma cell-derived nanovesicles (NVs), functioning as a potent immunostimulant. This in situ recruitment strategy overcomes the limitations of subcutaneous tumor vaccine injections and more effectively achieves antitumor immunity. Additionally, the hydrogel incorporates Chlorella extracts, enhancing its antimicrobial properties to prevent wound infections and promote healing. One of the key findings of our research is the dual functionality of Chlorella extracts; they not only expedite the healing process of infected wounds but also increase the hydrogel's ability to stimulate an antitumor immune response. Given the patient-specific nature of the blood clot and NVs, our hydrogel system offers customizable solutions for individual postoperative requirements. This personalized approach is highlighted by our study, which demonstrates the synergistic impact of the composite hydrogel on preventing melanoma recurrence and hastening wound healing, potentially transforming postsurgical melanoma management.

Programmed surface platform orchestrates anti-bacterial ability and time-sequential bone healing for implant-associated infection.

Implant-associated infection (IAI) has become an intractable challenge in clinic. The healing of IAI is a complex physiological process involving a series of spatiotemporal connected events. However, existing titanium-based implants in clinic suffer from poor antibacterial effect and single function. Herein, a versatile surface platform based on the presentation of sequential function is developed. Fabrication of titania nanotubes and poly-γ-glutamic acid (γ-PGA) achieves the efficient incorporation of silver ions (Ag+) and the pH-sensitive release in response to acidic bone infection microenvironment. The optimized PGA/Ag platform exhibits satisfactory biocompatibility and converts macrophages from pro-inflammatory M1 to pro-healing M2 phenotype during the subsequent healing stage, which creates a beneficial osteoimmune microenvironment and promotes angio/osteogenesis. Furthermore, the PGA/Ag platform mediates osteoblast/osteoclast coupling through inhibiting CCL3/CCR1 signaling. These biological effects synergistically improve osseointegration under bacterial infection in vivo, matching the healing process of IAI. Overall, the novel integrated PGA/Ag surface platform proposed in this study fulfills function cascades under pathological state and shows great potential in IAI therapy.

Tailored extracellular matrix-mimetic coating facilitates reendothelialization and tissue healing of cardiac occluders.

Minimally invasive transcatheter interventional therapy utilizing cardiac occluders represents the primary approach for addressing congenital heart defects and left atrial appendage (LAA) thrombosis. However, incomplete endothelialization and delayed tissue healing after occluder implantation collectively compromise clinical efficacy. In this study, we have customized a recombinant humanized collagen type I (rhCol I) and developed an rhCol I-based extracellular matrix (ECM)-mimetic coating. The innovative coating integrates metal-phenolic networks with anticoagulation and anti-inflammatory functions as a weak cross-linker, combining them with specifically engineered rhCol I that exhibits high cell adhesion activity and elicits a low inflammatory response. The amalgamation, driven by multiple forces, effectively serves to functionalize implantable materials, thereby responding positively to the microenvironment following occluder implantation. Experimental findings substantiate the coating's ability to sustain a prolonged anticoagulant effect, enhance the functionality of endothelial cells and cardiomyocyte, and modulate inflammatory responses by polarizing inflammatory cells into an anti-inflammatory phenotype. Notably, occluder implantation in a canine model confirms that the coating expedites reendothelialization process and promotes tissue healing. Collectively, this tailored ECM-mimetic coating presents a promising surface modification strategy for improving the clinical efficacy of cardiac occluders.

Chitosan-based hydrogel incorporated with polydopamine and protoporphyrin for photothermal-oxidation sterilization of bacteria-infected wound therapy.

Phototherapy has emerged as a potential treatment strategy for bacteria-infected wounds, but the inadequate bacteria-capturing ability and excessive damage to normal tissues from single phototherapy are huge limitations. To solve the issues, herein we report the design of chitosan-based hydrogel with bacteria capturing and combined photothermal/photodynamic sterilization functions. Such hydrogel is prepared by mixing chitosan (CS) as matrix, protoporphyrin (PpIX) as photosensitizer and polydopamine (PDA) as photothermal agent and then chemically cross-linking CS with glutaraldehyde. The resulting CS-PpIX-PDA hydrogel possesses a porous architecture (average pore porosity = 60.9 %), excellent swelling capabilities (swelling ratio = 1855 %) and rheological property (G' > G″). The hydrogel can effectively produce reactive oxygen species (ROS) under 660 nm light irradiation due to the photodynamic effect of PpIX. Owing to the presence of PDA, the hydrogel displays a photoabsorption range between 600 and 1500 nm and can generate maximal temperature of 60 °C within 10 min under 808 nm laser illumination (0.6 W/cm2) through photothermal effect. Besides, under synergetic illumination of 808/660 nm laser, CS-PpIX-PDA hydrogel can induce the death of 99.9999 % of E. coli and 99.99999 % of S. aureus. Importantly, when coated on the wound site, the hydrogel exhibits a remarkable bacteria-trapping ability due to its porous structure and the presence of amino groups on chitosan. Under the excitation of 660/808 nm, the combined photothermal and photodynamic effects can effectively eradicate bacteria. Simultaneously, the hydrogel also demonstrates anti-inflammatory properties and upregulates Heat Shock Protein 90 (HSP90) expression, thereby promoting collagen deposition and facilitating wound healing. Therefore, the study may provide some new insights into the development of multifunctional hydrogel for photothermal-oxidation sterilization of bacteria-infected wound therapy.

A self-healing composite solid electrolyte with dynamic three-dimensional inorganic/organic hybrid network for flexible all-solid-state lithium metal batteries.

Composite solid electrolytes (CSEs), which combine the advantages of solid polymer electrolytes and inorganic solid electrolytes, are considered to be promising electrolytes for all-solid-state lithium metal batteries. However, the current CSEs suffer from defects such as poor inorganic/organic interface compatibility, lithium dendrite growth, and easy damage of electrolyte membrane, which hinder the practical application of CSEs. Herein, a CSE (PBHL@LLZTO@DDB) with polyurethane (PBHL) as the polymer matrix and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) modified by silane coupling agent (DDB) as inorganic fillers (LLZTO@DDB) has been prepared. Disulfide bond exchange reactions between PBHL and LLZTO@DDB enable PBHL@LLZTO@DDB to form a dynamic three-dimensional (3D) inorganic/organic hybrid network, which promotes the uniform dispersion of LLZTO in PBHL@LLZTO@DDB, improves the Li+ conductivity (1.24 ± 0.08 × 10-4 S cm-1 at 30 â„ƒ), and broadens the electrochemical stability window (5.16 V vs. Li+/Li). Moreover, a combination of hydrogen bonds and disulfide bonds endows PBHL@LLZTO@DDB with excellent self-healing properties. As such, both all-solid-state symmetric and full cells exhibit excellent cycle performance at ambient temperature. More importantly, the healed PBHL@LLZTO@DDB can almost completely restore its original electrochemical properties, indicating its application potential in flexible electronic products.

Self-healing, piezoresistive and temperature responsive behaviour of chitosan/polyacrylic acid dynamic hydrogels.

Flexible electronics have introduced new challenges for efficient human-machine interactions. Hydrogels have emerged as prominent materials for electronic wearable applications due to their exceptional mechanical deformability and lightweight characteristics combined in some cases with conductive properties, and softness. Additionally, bio-interphases require multisensory response to stress, strain, temperature, and self-healing capacity. To mimic these properties, this work developed interpenetrated hydrogel networks composed of chitosan (CHI) and polyacrylic acid (PAA), combined with Fe (III) ions and varying amounts of NMBA (0-0.25 %), to achieve tailored conductivity (0.8-2.5 mS/cm), self-healing, self-standing and mechanical properties (E = 11.7-110 Pa and fracture strain = 64.9-1923 %) suitable for strain sensor applications. The results revealed a significant influence of the restrictive effect on the mobility of uncrosslinked chain segments, caused by Fe ions and NMBA, on the piezoresistance (GF 2.1-1.3) and self-healing capability of the gels. Interestingly, a transparent/turbid transition, driven by microphase separation that is characteristic of systems with high dynamic interactions, was encountered for the first time in these hydrogels. This transition was analyzed in relation to external temperature, water content, pH, and the influence of Fe ions and NMBA. The simultaneous sensitivity of these materials to temperature and pH, along with their piezoresistive and self-healing behaviour, can be highly valuable for multifunctional sensors in a wide range of applications.

Ionic aggregates induced room temperature autonomous self-healing elastic tape for reducing ankle sprain.

Traditional kinesiology tape (KT) is an elastic fabric tape that clinicians and sports trainers widely use for managing ankle sprains. However, inadequate mechanical properties, adhesive strength, water resistance, and micro-damage generation could affect the longevity of the tape on the skin during physical activity and sweating. Therefore, autonomous room-temperature self-healing elastomers with robust mechanical properties and adequate adhesion to the skin are highly desirable to replace traditional KT. Ionic aggregates were introduced into the polymer matrix via electrostatic attraction between polymer colloid and polyelectrolyte to achieve such elastic tape. These ionic aggregates act as physical crosslink points to enhance mechanical properties and dissociate at room temperature to provide self-healing functions. The obtained elastic tape possesses a tensile strength of 3.7 MPa, elongation of 940 %, toughness of 16.6 MJ∙m-3, and self-healing efficiency of 90 % for 2 h at room temperature. It also exhibits adequate reversible adhesion on the skin via van der Waals force and electrostatic interaction in both dry and wet conditions. The new elastic tapes have great potential in biomedical engineering for preventing and rehabilitating ankle sprain.

Self-powered strain sensing devices with wireless transmission: DIW-printed conductive hydrogel electrodes featuring stretchable and self-healing properties.

With rapid advancements in health and human-computer interaction, wearable electronic skins (e-skins) designed for application on the human body provide a platform for real-time detection of physiological signals. Wearable strain sensors, integral functional units within e-skins, can be integrated with Internet of Things (IoT) technology to broaden the applications for human body monitoring. A significant challenge lies in the reliance of most existing wearable strain sensors on rigid external power supplies, limiting their practical flexibility. In this study, we present an innovative strategy to fabricate glutaraldehyde (GA)-poly(vinyl alcohol) (PVA)/cellulose nanocrystals (CNC)/Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) conductive hydrogels through multiple hydrogen bonding systems. Combining the advantageous rheological properties of the precursor solution and the high specific surface area after freeze-thaw cycling, we have created a self-powered sensing system prepared by large-area printing using direct ink writing (DIW) printing. The resulting conductive hydrogel exhibits commendable mechanical properties (411 KPa), impressive stretchability (580 %), and robust self-healing capabilities (>98.3 %). The strain sensor, derived from the conductive hydrogel, demonstrates a gauge factor (GF) of 2.5 within a stretching range of 0-580 %. Additionally, the resultant supercapacitor displays a peak energy density of 0.131 mWh/cm3 at a power density of 3.6 mW/cm3. Benefiting from its elevated strain response and remarkable power density features, this self-powered strain sensing system enables the real-time monitoring of human joint motion. The incorporation of a 5G transmission module enhances its capabilities for remote data monitoring, thereby contributing to the progress of wireless tracking technologies for self-powered electronic skin.

Self-passivation/self-delivery/self-healing anticorrosion polymer coating for marine applications.

Corrosion of steel in the marine environment greatly reduces their service life. Polymeric coatings are the most popular anticorrosion technology, but seawater penetration cannot be prohibited because of the distinct stacking structure of the macromolecular chains. In this context, a novel anticorrosive hyperbranched polyurethane-based coating with dopamine (DOPA) at the terminals is prepared herein. The built-in DOPA is able to capture the iron ions released from the corroded substrate and form DOPA-Fe3+ complexation, which further cooperates with the surrounding seawater and imparts self-passivation, self-delivery and self-healing capabilities to the coating. Under the joint action of these measures, the corrosion of tinplate (serving as the steel model) is reduced to a record-low level (corrosion current = 1 × 10-9 A cm-2, corrosion rate = 1 × 10-5 mm year-1). Conceptually, the present dynamic active anticorrosion strategy greatly outperforms the traditional static passive approach, and turns the unfavorable but unavoidable seawater into a favorable factor, which paves the way for the development of long-lasting marine coatings.

Construction of a one-stop N-doped negatively charged carbon dot nanoplatform with antibacterial and anti-inflammatory dual activities for wound infection based on biocompatibility.

The development of bacterial resistance significantly contributes to the persistence of infections. Although previous studies have highlighted the benefits of metal-doped positive carbon nanodots in managing bacterial wound infections, their mechanism of action is relatively simple and they may pose potential hazards to human cells. Therefore, it is essential to develop a one-stop carbon dot nanoplatform that offers high biocompatibility, antibacterial properties, and anti-inflammatory activities for wound infection management. This study explores the antibacterial efficacy, without detectable resistance, and wound-healing potential of nitrogen-doped (N-doped) negatively charged carbon dots (TPP-CDs). These carbon dots are synthesized using tannic acid (TA), polyethylene polyamine, and polyethylene glycol (PEG) as precursors, with a focus on their biocompatibility. Numerous systematic studies have shown that TPP-CDs can effectively destroy bacterial biofilms and deoxyribonucleic acid (DNA), while also inducing oxidative stress, leading to a potent antimicrobial effect. TPP-CDs also demonstrate the ability to scavenge excess free radicals, promote cellular proliferation, and inhibit inflammatory factors, all of which contribute to improved wound healing. TPP-CDs also demonstrate favorable cell imaging capabilities. These findings suggest that N-doped negatively charged TPP-CDs hold significant potential for treating bacterial infections and offer practical insights for their application in the medical field.

Keratinocyte Integrin α3ß1 Promotes Efficient Healing of Wound Epidermis.

To date, studies of the role for epidermal integrin α3ß1 in cutaneous wound re-epithelialization have produced conflicting results: wound studies in skin from global α3-null neonatal mice have implicated the integrin in promoting timely wound re-epithelialization, whereas studies in adult mice with constitutive, epidermal-specific α3ß1 deletion have not. The objective of this study was to utilize a model of inducible α3ß1 deletion in the epidermis to clarify the role of α3ß1 in the healing of adult wounds. We utilized the recently developed transgenic K14Cre-ERT::α3flx/flx mice (ie, inducible α3 epidermal knockout), permitting us to delete floxed Itga3 alleles (α3flx/flx) from epidermis just prior to wounding with topical treatment of 4-hydroxytamoxifen. This allows for the elucidation of α3ß1-dependent wound healing in adult skin, free from compensatory mechanisms that may occur after embryonic deletion of epidermal α3ß1 in the widely used constitutive α3ß1-knockout mouse. We found that re-epithelializing wound gaps are larger in inducible α3 epidermal knockout mice than in control mice, indicating delayed healing, and that epidermal integrin α3ß1 promotes healing of wounds, at least in part by enhancing keratinocyte proliferation. This work provides essential rationale for future studies to investigate integrin α3ß1 as a therapeutic target to facilitate wound healing.

MMP-9 responsive hydrogel promotes diabetic wound healing by suppressing ferroptosis of endothelial cells.

Ferroptosis plays a crucial role in the progression of diabetic wounds, suggesting potential therapeutic strategies to target ferroptosis. Transient receptor potential ankyrin 1 (TRPA1) is a non-selective calcium channel that acts as a receptor for a variety of physical or chemical stimuli. Cinnamaldehyde (CA) is a specific TRPA1 agonist. In in vitro experiments, we observed that high glucose (HG) treatment induced endothelial cell ferroptosis, impairing cell function. CA successfully inhibited endothelial cell ferroptosis, improving migration, proliferation, and tube formation. Further mechanistic studies showed that CA-activated TRPA1-induced Ca2+ influx promoted the phosphorylation of calmodulin-dependent protein kinase II (CaMKII) and nuclear factor-E 2-related factor 2 (Nrf2) translocation, which contributed to the elevation of glutathione peroxidase 4 (GPX4), leading to the inhibition of endothelial cell ferroptosis. In addition, CA was incorporated into an MMP-9-responsive injectable duplex hybrid hydrogel (CA@HA-Gel), allowing its efficient sustained release into diabetic wounds in an inflammation-responsive manner. The results showed that CA@HA-Gel inhibited wound endothelial cell ferroptosis and significantly promoted diabetic wound healing. In summary, the results presented in this study emphasize the potential therapeutic application of CA@HA-Gel in the treatment of diseases associated with ferroptosis.

Self-assembling chitosan based injectable and expandable sponge with antimicrobial property for hemostasis and wound healing.

Chitosan and chitosan derivative are widely used in hemostasis, antibiosis and wound repair for its good biocompatibility and unique effect. However, the preparation of chitosan based hemostatic materials or wound dressings generally involves chemical crosslinking agent introduction, acid residue or complicated preparation process, which limits its clinical application. In this study, an injectable and expandable chitosan sponge was constructed by chitosan (CS) and quaternized chitosan (QCS) self-assembly without acid retention and chemical crosslinker introduction. In the neutral condition, the hydrogen bond of CS molecules can act as the driving force to form cross-linking network, and the QCS was introduced to regulate the hydrogen bond of CS to avoid the excessive aggregation. The porous QCS/CS sponge was obtained by freeze-drying of the self-assembly QCS/CS hydrogel. The sponge exhibited high expansibility, injectability and water/blood triggered shape memory property. Due to the introduction of QCS, the sponge showed good antibacterial properties, which can protect the wound from bacterial invasion. The convenient and green preparation method of injectable and expandable QCS/CS sponge is a potential method for the treatment of hemostasis and wound healing.

All-natural hydrogel composed of carboxymethyl chitosan and oxidized dextran for promoting wound healing by immune-microenvironment regulation.

Chronic wound treatment has always been a major clinical challenge owing to complex and dynamic wound microenvironment. The design and development of effective management with antimicrobial activity, ROS-scavenging and regulation immune response is vital for tissue repair. Herein, we developed puerarin (PUE) loaded a double network hydrogel consisting of methacrylated carboxymethyl chitosan and oxidized dextran with Schiff base and photo-crosslinking reaction. The composite hydrogel presented fast self-healing and outstanding compressive performance to bear deformation. The hydrogel exhibits a cumulative drug release pattern with biphasic release, which offers great potential for accelerating tissue healing at all stages of wounding. In addition, the hydrogel has good biocompatibility, antimicrobial ability and tube-forming ability in vitro. The full-thickness skin wound model of Staphylococcus aureus infection showed that the hydrogel dressing can accelerate tissue repair. This study demonstrated that the design of combing natural biomacromolecules with traditional Chinese medicine could be severed as a promising candidate biomaterial for skin tissue recovery.

Biomimetic superparamagnetic gelatin/chitosan asymmetric fibrous membrane for accelerating wound healing under static magnetic field.

The single structure, poor mechanical properties, and low biological activity of wound dressings usually lead to unsatisfactory treatment effects. Gelatin and chitosan possess excellent biofunction, but they lack sufficient mechanical support. Magnetic biomaterials and magnetic fields have shown surprising tissue repair potential. Herein, inspired by the skin structure and considering the bioactive composition, a superparamagnetic asymmetric membrane was constructed by incorporating gelatin, chitosan, and magnetic Fe3O4 nanoparticles. The proposed membrane exhibited a high degree of asymmetry, achieving functional diversification. The surface of the top layer was highly hydrophobic as an isolation barrier. The top layer consisted of dense fibrous chitosan with high mechanical strength and excellent antibacterial properties. The bottom layer was composed of gelatin sponge with distributed magnetic nanoparticles, possessing high porosity and swelling ratio to effectively absorb tissue exudates and support cell growth. Furthermore, the membrane demonstrated significant promotion of human dermal fibroblast proliferation under a static magnetic field. In a full-thickness mouse skin wound model, the membrane effectively accelerated wound healing with reduced wound area, abundant collagen disposition, and enhanced vascularization. Therefore, the superparamagnetic gelatin/chitosan asymmetric membrane with a biomimetic structure and function exhibits remarkable superiority and provides a promising approach to effective wound healing.

Enhanced diabetic foot ulcer treatment with a chitosan-based thermosensitive hydrogel loaded self-assembled multi-functional nanoparticles for antibacterial and angiogenic effects.

Inhibiting bacterial growth and promoting angiogenesis are essential for enhancing wound healing in diabetic patients. Excessive oxidative stress at the wound site can also lead to an accumulation of reactive oxygen species. To address these challenges, a smart thermosensitive hydrogel loaded with therapeutic agents was developed. This formulation features self-assembled nanoparticles named CIZ, consisting of chlorogenic acid (CA), indocyanine green (ICG), and zinc ions (Zn2+). These nanoparticles are loaded into a chitosan-ß-glycerophosphate hydrogel, named CIZ@G, which enables rapid gel formation under photothermal effects. The hydrogel demonstrates good biocompatibility and effectively releases drugs into diabetic foot ulcers (DFU) wound. Benefiting from the dual actions of CA and zinc ions, the hydrogel exhibits potent antioxidative and anti-inflammatory effects, enhances the expression of vascular endothelial growth factor (VEGF) and Platelet endothelial cell adhesion molecule-1 (CD31), and promotes angiogenesis. Both in vitro and in vivo experiments confirm that CIZ@G can effectively inhibit the growth of Staphylococcus aureus post-laser irradiation and accelerate wound remodeling within 14 days. This approach offers a new strategy for the treatment of diabetic foot ulcers (DFU), potentially transforming patient care in this challenging clinical area.

Self-healing cellulose-based hydrogels: From molecular design to multifarious applications.

Self-healing cellulose-based hydrogels (SHCHs) exhibit wide-ranging potential applications in the fields of biomedicine, environmental management, energy storage, and smart materials due to their unique physicochemical properties and biocompatibility. This review delves into the molecular design principles, performance characteristics, and diverse applications of SHCHs. Firstly, the molecular structure and physicochemical properties of cellulose are analyzed, along with strategies for achieving self-healing properties through molecular design, with particular emphasis on the importance of self-healing mechanisms. Subsequently, methods for optimizing the performance of SHCHs through chemical modification, composite reinforcement, stimulus responsiveness, and functional integration technologies are discussed in detail. Furthermore, applications of SHCHs in drug delivery, tissue engineering, wound healing, smart sensing, supercapacitors, electronic circuits, anti-counterfeiting systems, oil/water separation, and food packaging are explored. Finally, future research directions for SHCHs are outlined, including the innovative development of new SHCHs, in-depth elucidation of cooperative strengthening mechanisms, a further expansion of application scope, and the establishment of intelligent systems. This review provides researchers with a comprehensive overview of SHCHs and serves as a reference and guide for future research and development.

Injectable Salecan/hyaluronic acid-based hydrogels with antibacterial, rapid self-healing, pH-responsive and controllable drug release capability for infected wound repair.

Designing materials for wound dressings with superior therapeutic benefits, self-healing and injectable characteristics is important in clinical practice. Herein, a new self-healing injectable hydrogel was prepared via thermal treatment and dynamic Schiff base reaction by mixing oxidized hyaluronic acid (OHA) and hydrazided Salecan (Sal-ADH). The versatility of the wound dressing was confirmed by studying the inherent rheological properties, high swelling rate, sustained-release behavior of the drug, pH/hyaluronidase-dependent biodegradation, in vitro antimicrobial as well as in vivo wound healing performance. The presence of the antimicrobial drug polyhexamethylene biguanide (PHMB) conferred good antimicrobial properties to the Sal-ADH/OHA/PHMB (SOP) hydrogel, which could effectively prevent wound infection (the width of the inhibition circle of SOP-0.20 hydrogel was 4.97 mm, 5.93 mm for Staphylococcus aureus and Escherichia coli, respectively). The findings suggested that SOP hydrogel exhibited remarkable self-healing and injectability properties, as well as excellent hemostasis and biocompatibility. In vivo experiments indicated that the application of SOP hydrogels would obviously accelerate wound healing and attenuate the inflammatory response while increasing collagen deposition and angiogenesis. Altogether, antibacterial SOP hydrogels with moderate mechanical properties, pH-responsive release, excellent injectability, exceptional self-healing ability and anti-inflammatory effects could expand potential applications of injectable hydrogels in the biomedical field.