Composite Dressings Research Articles

In Vivo Performance of Microstructured Bacterial Cellulose-Silk Sericin Wound Dressing: Effects on Fibrosis and Scar Formation

Improved healing rates are obtained upon the application of the composite dressings as compared to pure BC. mBC-SS2 prevents the excessive wound contraction which leads to hypertrophied neo-tissue formation when rBC-SS2 is used. The collagen fibers are aligned along the width of microgroove of mBC and its composites while anarchic deposited in the presence of rBC and its composites. Relatively to rBC-SS2, mBC-SS2 constitutes an improved dressing with abilities of inducing rapid wound healing and reducing the risk of excessive fibrosis and scar formation.

Study of double-bonded carboxymethyl chitosan/cysteamine-modified chondroitin sulfate composite dressing for hemostatic application

Stanching severe traumatic bleeding requires hemostatic materials that can provide rapid and efficient hemostasis. However, most currently available hemostatic agents exhibit low efficiency and poor biocompatibility. In this study, a novel carboxymethyl chitosan modified with methacrylic anhydride (double-bonded carboxymethyl chitosan)/cysteamine-modified chondroitin sulfate (Me-CMC/CSS) rapid hemostatic dressing was developed using thiol-ene click chemistry. The freeze-dried Me-CMC/CSS dressings absorbed water rapidly and transformed into soft hydrogels that could seal wounds, achieving good hemostasis. The relative blood clotting index of the optimal Me-CMC/CSS dressing was decreased by 53% (p < 0.001) and 29% compared with a pure Me-CMC dressing and a commercial hemostatic gelatin sponge, respectively. In a rat liver hemorrhage model, the Me-CMC/CSS dressing stopped bleeding rapidly, and the total blood loss was significantly decreased by 92% (p < 0.0001) compared with the untreated group and was lower than that with gelatin sponge treatment. The Me-CMC/CSS dressing also exhibited a higher ability to adhere to platelets than the gelatin sponge. Furthermore, the Me-CMC/CSS dressing exhibited good hemocompatibility and cytocompatibility. The results indicate that the composite dressings can be potentially applied as rapid hemostatic materials.

Development of Antibacterial and Hemostatic PCL/Zein/ZnO‐Quaternary Ammonium Salts NPs Composite Mats as Wound Dressings

AbstractWound dressings are usually employed to maintain suitable conditions around the injured skin to accelerate wound healing. This paper aims to report functional composite dressings combined with polycaprolactone (PCL) nanofibers, self‐assembly zein coating and modified ZnO nanoparticles (ZnO NPs) for wound management. The synthetic compounds and prepared composite dressings are characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy. Meanwhile, the water vapor transmission rate, hemostatic performance, antibacterial activity, and cytocompatibility of the composite dressings are systematically tested to evaluate their applicability in wound treatment. The results show that the multilayer dressings can retain moisture and prevent excessive dehydration of wound. In vitro hemostatic test is conducted, and the enhanced blood clotting capacity and the activation of platelets indicate that the desired dressings are able to control hemorrhaging from wound. Meanwhile, the composite dressings with excellent biocidal efficacy against Gram‐positive Staphylococcus aureus (6.01 Log within 30 min) and Gram‐negative Escherichia coli O157:H7 (6.04 Log within 30 min) can effectively prevent wound infection. Furthermore, the dressings show no toxicity which are evidenced in hemolysis and cytocompatibility evaluation, and have potential application for wound healing.

PREDICTIVE MATEHMATICAL MODEL FOR ABSORBANT SUBSTRATE ACHIEVEMENT, THROUGH ELECTROSPINNING PROCESS

The new generations of wound dressings aim to create an optimal environment that allows epithelial cells to move easily in order to support regeneration. Such optimal conditions include a humid environment around the wound bed, efficient oxygen circulation to help regenerate cells and tissues, and low bacterial contamination. Composite matrices have several layers and can be used as primary or secondary dressings. Most composite dressings have three layers, respectively a semi-adherent or non-adherent layer, an absorbent layer, and a bacterial barrier layer. A method to obtaining these materials, which can be assimilated to layerby- layer deposition, or which can be operated in this regime, is represented by electrospinning. However, the deposition technique by electrospinning on textile surfaces (fabrics or nonwovens) raises some problems related to the electrostatic behaviour of textile fibres with dielectric properties. In this case, the characteristics of the jet are affected directly proportional with the thickness of the textile material, resulting in defects of nano- or micro-fibrillar deposition, such as unevenness and/or sputter (formation of drops, which are deposited in mixture with electro spun fibres). The article presents a mathematical model that predicts the diameter of the fibres in the composition of the absorbent layer of the multilayer matrix structure for the treatment of burns or gunshot wounds, taking into account the nonlinear relationships between the parameters explained above and specific theories of electrodynamics for thin profiles (for instance, those used in aeronautics) for the prediction of the behaviour of the electrospinning jet.

A collagen-based bi-layered composite dressing for accelerated wound healing

Aim of the studyThe aim of the study was to fabricate collagen-based composite dressings, evaluate the efficiency for wound healing and reveal the mechanism of promoting wound healing. Materials and methodsAn innovative bi-layered composite wound dressing was developed using two marine biomacromolecules (collagen and chitosan). Full-thickness skin defect model was performed to evaluate the wound healing activity in vivo. The levels of inflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin (IL-1, IL-6, IL-8) and growth factors like transforming growth factor beta (TGF-β), vascular epidermal growth factor (VEGF) and basic fibroblast growth factor (bFGF) were quantified by ELISA assays. The total amount of collagen was quantified by hydroxyproline content. The proliferation and viability of fibroblast cells cultured on collagen sponges were determined by CCK-8 assay. ResultsThe results of wound closure and histopathological analysis indicated that non-crosslinked collagen-based bi-layered composite dressing stimulated wound healing, accelerated re-epithelialization and accomplished wound healing within a time span of 28 days. The results of levels of inflammatory cytokines and growth factors showed that collagen-based composite dressings could reduce the inflammatory response and upregulate growth factors levels to accelerate the wound healing. The results of hydroxyproline content and CCK-8 assay indicated that collagen-based composite dressings could also promote collagen synthesis and fibroblasts viability and proliferation. ConclusionThe non-crosslinked collagen-based bi-layered composite dressing could be applied for an efficient and ideal wound dressing. Therefore, the findings provided the essential theoretical basis for the potential of collagen-based composite dressing applied in wound healing fields.

In situ photo-crosslinking hydrogel with rapid healing, antibacterial, and hemostatic activities

Abstract Uncontrollable bleeding is still the main cause of post-traumatic deaths due to the blood loss. Moreover, infectious complication of wound is also still a challenging problem for wound healing. Nevertheless, the currently available hemostasis drugs or materials cannot stanch bleeding well due to single function, slow in effectiveness, adhere to wounds easily, poor gas permeability, etc. Therefore, it is of a great significance to utilize a biomedical hemostatic material that can stop bleeding quickly, preventing from bacterial infections, and with good biocompatibility properties. Herein chitosan (CS) was modified with gallic acid (GA) and thrombin (TB) to prepare an antibacterial hemostatic composite dressing. The CS-based composite hydrogel dressing was obtained by acylation modification, ultraviolet curing crosslinking method and physical mixing. The in vitro results showed that our prepared CS-based composite hydrogel has obvious burst release and good degradation property. Moreover, the in vivo results showed that it has a strong antibacterial property that is much better than single CS, and it can stop bleeding in 1 min which can promote wound healing. Therefore, the findings of this study is expected to contribute to the future designing of biomedical hemostatic materials with improved properties.

Preparation and evaluation of an innovative antibacterial bi-layered composite dressing for skin wound healing

Aim of the studyThe aim of the current study was to develop collagen-based bi-layered composite dressings with antibacterial property and evaluate the efficiency for wound healing. Materials and methodsA bi-layered composite wound dressing was fabricated using two marine biomacromolecules (collagen and chitosan or carboxymethyl chitosan). Non-crosslinked and N-Ethyl-N'-(3-dimethylaminopropyl) carbodiimide/N-Hydroxy succinimide (EDC/NHS) cross-linked collagen sponges fabricated by vacuum freeze-drying technology was used as the inner layer. The medical spun-laced nonwoven coated with chitosan and carboxymethyl chitosan was used as the outer layer. The antibacterial activities against E. coli and S. aureus were evaluated by the inhibition zone assay. Deep second-degree scald model was performed to evaluate the efficiency of bi-layered composite dressings for wound healing. ResultsIn view of comprehensive evaluation of appearance and in vitro antibacterial activity, medical spun-laced nonwoven coated with 3% of chitosan solution was chosen to be used as the optimized preparation conditions to produce the outer layer of composite dressing, which acted as a barrier against microorganisms and provided mechanical support. Furthermore, the results of wound closure and histopathological analysis indicated that EDC/NHS cross-linked collagen-based bi-layered composite dressing was superior to non-crosslinked and commercial products, which stimulated the wound healing process and accomplished deep second-degree scalded skin healing within a time span of 28 days. ConclusionThe EDC/NHS cross-linked collagen-based bi-layered composite dressing had immense potential to be applied for an ideal wound dressing for more efficient and faster wound healing. Therefore, the findings provided the essential theoretical basis for great potential of collagen-based composite dressing used in wound healing applications.

Bacterial Nanocellulose-Enhanced Alginate Double-Network Hydrogels Cross-Linked with Six Metal Cations for Antibacterial Wound Dressing.

Alginate (Alg) and bacterial nanocellulose (BNC) have exhibited great potential in biomedical applications, especially wound dressing. Non-toxicity and a moisture-maintaining nature are common features making them favorable for functional dressing fabrication. BNC is a natural biopolymer that promotes major advances to the current and future biomedical materials, especially in a flat or tubular membrane form with excellent mechanical strength at hydrated state. The main drawback limiting wide applications of both BNC and Alg is the lack of antibacterial activity, furthermore, the inherent poor mechanical property of Alg leads to the requirement of a secondary dressing in clinical treatment. To fabricate composite dressings with antibacterial activity and better mechanical properties, sodium alginate was efficiently incorporated into the BNC matrix using a time-saving vacuum suction method followed by cross-linking through immersion in separate solutions of six cations (manganese, cobalt, copper, zinc, silver, and cerium). The results showed the fabricated composites had not only pH-responsive antibacterial activities but also improved mechanical properties, which are capable of acting as smart dressings. All composites showed non-toxicity toward fibroblast cells. Rat model evaluation showed the skin wounds covered by the dressings healed faster than by BNC.

Layer-by-layer coating of carboxymethyl chitosan-gelatin-alginate on cotton gauze for hemostasis and wound healing

We developed a hemostatic material able to quickly stop wound bleeding by successively constructing carboxymethyl chitosan (CMC), gelatin, and alginate onto a cotton gauze surface through a simple layer-by-layer (LbL) process. Briefly, we grafted CMC onto the cotton fibers through an esterification reaction with the hydroxyl groups of the cellulose chains, and then built a gelatin layer on the CMC layer by the ionic reactions with CMC. Finally, we integrated alginate by the lamellar structure through the cross-linking reactions caused by the Ca2+ ions permeated from the gelatin layer. Characterization analyses demonstrated that the resulting composite dressing possessed high fluid absorption, excellent biocompatibility, and hemocompatibility. A better hemostatic performance was also revealed in animal tests compared with cotton gauze, and it showed a short hemostasis time and a small amount of blood loss in the mouse liver injury model and mouse-tail amputation model. Moreover, the composite dressing also exhibited a significant promotion effect of wound healing in a mouse defect wound model. This new composite dressing, which was prepared by natural raw materials, is a promising candidate for wound dressing and demonstrated great potential in medical applications.

Bioactive Self‐Pumping Composite Wound Dressings with Micropore Array Modified Janus Membrane for Enhanced Diabetic Wound Healing

AbstractTreatment of chronic wounds such as diabetic wounds with large volumes of biofluids is a significant clinical challenge due to ischemia caused by localized edema. To alleviate edema and stimulate angiogenesis, a four‐layer composite dressing is designed with a micropore array modified Janus membrane for self‐pumping and bioactive ion backflow, a superabsorbent layer for high capacity water absorption, and a bioactive layer containing bioglass for stimulating angiogenesis. The modified Janus membrane not only allows wound exudates transport from wound bed to the dressing, but also enables controlled backflow of bioactive ion containing fluid to the wound bed for stimulating angiogenesis. The in vivo experiment confirms the function of composite dressing in reducing wound edema, stimulating blood vessel formation and promoting diabetic wound healing. These results demonstrate that the novel composite dressing is a promising wound healing biomaterial for promoting chronic wound healing, and the unique characteristics of the micropore arrayed Janus membrane may extend its applications in biomedicine.

Biomaterial-based dressings as vehicle for chitosan-encapsulated cabreuva essential oil: Cytotoxicity and regenerative activity

Chitosan-based emulsions functionalized with cabreuva essential oil (Myrocarpus fastigiatus) assembled with poly(vinyl alcohol) (PVA) were tailor-made to obtain a smooth, flexible and thin wound dressings capable for acting as a delivery vehicle. The cabreuva essential oil is composed mainly of trans-nerolidol, a natural compound with antimicrobial capacity that acts as a skin penetration enhancer. During the application of the dressing on skin explants, the penetration profile of cabreuva was analyzed through ex-vivo diffusion assays. Furthermore, the in-vivo essential oil delivery was followed by means of ATR-FTIR.The addition of chitosan-based emulsions produced modifications in the properties of the composite dressings associated with the water affinity and gas permeability as well as in the mechanical behavior. The dressing functionalized with cabreuva essential oil combined with chitosan proved its effectiveness against microorganisms such as S. aureus and S. epidermidis, capacity to produce cell regeneration after 24 h of contact time, and no cytotoxicity in HaCaT cells. The material developed could be used in superficial burns or minor wounds such as dressings due to its demonstrated functionality as controlled release devices of the cabreuva essential oil.

Polymeric Composite Dressings Containing Calcium-Releasing Nanoparticles Accelerate Wound Healing in Diabetic Mice.

Objective: Wound healing is a complex process that involves the interaction between different cell types and bioactive factors. Impaired wound healing is characterized by a loss in synchronization of these interactions, resulting in nonhealing chronic wounds. Chronic wounds are a socioeconomic burden, one of the most prominent clinical manifestations of diabetes, however, they lack satisfactory treatment options. The objective of this study was to develop polymeric composites that deliver ions having wound healing properties and evaluate its performance using a pressure ulcer model in diabetic mice. Approach: To develop a polymeric composite wound dressing containing ion-releasing nanoparticles for chronic wound healing. This composite was chemically and physically characterized and evaluated using a pressure ulcer wound model in diabetic (db/db) mice to explore their potential as novel wound dressing. Results: This dressing exhibits a controlled ion release and a good in vitro bioactivity. The polymeric composite dressing treatment stimulates angiogenesis, collagen synthesis, granulation tissue formation, and accelerates wound closure of ischemic wounds created in diabetic mice. In addition, the performance of the newly designed composite is remarkably better than a commercially available dressing frequently used for the treatment of low-exuding chronic wounds. Innovation: The developed nanoplatforms are cell- and growth factor free and control the host microenvironment resulting in enhanced wound healing. These nanoplatforms are available by cost-effective synthesis with a defined composition, offering an additional advantage in potential clinical application. Conclusion: Based on the obtained results, these polymeric composites offer an optimum approach for chronic wound healing without adding cells or external biological factors.

Erratum: Majumder, S. et al. Zinc Oxide Nanoparticles Functionalized on Hydrogel Grafted Silk Fibroin Fabrics as Efficient Composite Dressing. Biomolecules 2020, 10, 710

The authors wish to make the following correction to this paper [...].

Preparation and characterization of borosilicate-bioglass-incorporated sodium alginate composite wound dressing for accelerated full-thickness skin wound healing

Full-thickness skin injury is a serious and intractable clinical problem. Wound dressing is urgently needed to treat serious skin defects or induce skin reconstruction. For the first time, we demonstrated a borosilicate bioglass (BBG)-incorporated sodium alginate (SA) wound dressing by a simple and effective technique for accelerated wound healing. The physical and chemical properties, in vitro and in vivo properties of SA-BBG composite wound dressing have been investigated. The results show that the SA-BBG composite dressing possesses good water absorption performance. The boron and silicon ions in BBG can maintain stable and sustained release. Most importantly, the SA-BBG composite wound dressing shows outstanding wound healing ability in full-thickness skin defects in rats. The wounds treated with SA-BBG composite dressing groups had almost closed at day 15. When the ratio of sodium alginate to bioglass in the sponge is 3:1, the wound healing effect is the best. In conclusion, the SA-BBG composite dressing shows great potential for application in skin wound healing and SA3BBG works best.

Zinc Oxide Nanoparticles Functionalized on Hydrogel Grafted Silk Fibroin Fabrics as Efficient Composite Dressing.

Recent advances in woundcare is targeted towards developing active-dressings, where multiple components are combined to provide a suitable environment for rapid healing. The aim of the present research is to study the preparation of biomimic composite wound dressings by the grafting of hydrogel on silk fibroin fabric. The swelling ability of hydrogel grafted silk fibroin fabric was optimized by changing the initiator concentration. In order to impart antimicrobial properties, these dressing are further coated sono-chemically with zinc oxide nanoparticles. The water vapor transmission rate of the prepared samples was measured. The conformation of silk fibroin proteins after grafting with hydrogel was also confirmed using Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the zinc oxide-coated silk fibroin fabric and hydrogel-coated silk fibroin was studied using Scanning Electron Microscope (SEM). The antimicrobial activity of the zinc oxide-coated samples was studied against E coli. The cytocompatibility of the prepared dressing materials were evaluated using L929 fibroblast cells. MTT assay and phase contrast microscopic studies showed that the adherence, growth, and proliferation of the L929 fibroblast cells that were seeded on zinc oxide nanoparticles on the functionalized hydrogel-coated silk fibroin dressing was significantly higher than that of pure silk fibroin due to the highly porous, bio-mimic structure that allowed ease of passage of nutrients, growth factors, metabolites, and the exchange of gases which is beneficial for successful regeneration of damaged tissues. The expression of TNF-α and IL-2 were not significantly higher than that of control. The proposed composite dressing would be a promising material for wound dressing and regenerative medicine but in order to prove the efficacy of these materials, more in vivo experiments and clinical tests are required to be conducted in future.

Ciprofloxacin-intercalated layered double hydroxide-in-hybrid films as composite dressings for controlled antimicrobial topical delivery.

Films based on biopolymers and loaded with antimicrobial agents are convenient pharmaceutical dosage forms for topical application. Inorganic carriers loaded with these agents lead to composite materials, which combined with polymers produce further functionality. Here, hybrid composite films based on layered double hydroxide (LDH) and hyaluronan (HS) as ciprofloxacin (Cip) delivery systems were studied as an alternative for prophylaxis and treatment of opportunistic infections in wounds. Cip-intercalated Zn-Al LDH (LDH-Cip), with high drug loading and crystallinity, were obtained by a precipitation at variable pH method, and then included in a HS dispersion for obtaining the hybrid composite films by solvent casting. Physicochemical characterization of films showed that a composite material where the HS acted as matrix and LDH-Cip aggregates acted as filler were obtained. LDH-Cip were uniformly dispersed along the (LDH-Cip)/HS films, which exhibited roughness in their surface, increasing their swelling capacity in PBS pH=5.8. Controlled releases of Cip toward PBS at pH=5.8 and 7.4 were obtained, and the best fits for the release profiles were found with Higuchi and Korsmeyer-Peppas models, respectively. (LDH-Cip)/HS films exhibited antimicrobial activity against S. aureus. These films would then provide sustained release of Cip after topical administration, maintaining a suitable level of antibacterial activity, combined with the wound healing properties of the HS. The interesting properties shown by the (LDH-Cip)/HS films make them a promising alternative for application in skin wounds.

Cytotoxicity and hemostatic activity of chitosan/carrageenan composite wound healing dressing for traumatic hemorrhage

Hemorrhage remains a big threat to trauma patients, especially in combat fields. Therefore, we formulated a biocompatible and biopolymer based chitosan/carrageenan composite dressing. This dressing was fabricated using freeze-drying that will serve as a promising material to promote hemostasis and tissue growth required during hemorrhage. The efficacy of dressing was evaluated for its physiochemical analysis, surface morphology, and biodegradability. Further, human dermal fibroblast cells were seeded on dressing and demonstrated non-toxic effects on the cells by showing enhanced cell attachment and proliferation. In vitro hemostatic properties of the dressing were analyzed by human Thrombin-Antithrombin assay. The dressing formed showed steady blood coagulation implying red blood cells and platelet adhesion that helped in thrombin formation, which is responsible for enhancing wound healing. Thus, it is concluded that the composite dressing can be a potent combination to accelerate hemostatic activity against hemorrhage and promote tissue growth for effective wound healing.

Povidone iodine loaded film-forming topical gel and evaluation of its chemical stability

The main aim of this study was to develop Povidone Iodine loaded film-forming gel for excellent wound healing property with various formulations, and corresponding application stratification was prepared with Povidone Iodine, polyethylene glycol-400, polyethylene glycol-4000, aloe vera, and honey. Povidone Iodine is a broad spectrum antiseptic for topical application in the treatment and prevention of infection in wounds. Among the antiseptic and antimicrobial substances, Povidone-Iodine still occupies its position of lasting importance in everyday human and veterinary medicine. Povidone-iodine products display the broadest spectrum of antimicrobial effect with high clinical efficacy together with extremely low toxicity in clinical practice. The purpose served by dressing includes protecting wounds, promoting healing, and providing, retaining, or removing moisture. Wound repairing is a complex process involving an integrated response by many different cell types and growth factors to achieve rapid restoration of skin integrity and protective function after injury. In recent years, there have been tremendous advances in the design and composition of bandages and dressings, and there are numerous wound care materials. Some wound dressing types are biosynthetic dressings, composite dressings, gauze, hydrocolloid dressings, hydrogels, transparent films, etc. Povidone Iodine is completely soluble in cold and mild-warm water, ethyl alcohol, Iso propyl alcohol, Polyethylene glycol, and glycerol. The developed Povidone Iodine loaded film-forming gel was evaluated for their physical and chemical stability. The film-forming optimized gel formulation composed of povidone-iodine, polyethylene glycol-400, polyethylene glycol-4000, aloe vera, and honey and this composition provides suitable consistency, spreadability, and adhesiveness. The prepared trials were coded PGAH-01, PGAH-02, PGAH-03, PGAH-04, and PGAH-05, respectively. Among these all formulations, the PGAH-04 formulation parameters was found within the limit.

Advanced nursing recovery therapy in the field of nanotechnology based on tetracycline hydrochloride type drugs

With the development of wound care theory and practice methods, the development of new materials and the improvement of sustained release and controlled release technologies, medical dressings will develop in the direction of multi-functionality, diversification and intelligence. This has also promoted the development of clinical care, better service for wound patients, new dressings, and new methods for wound care. Among many new dressings, nanotechnology-based polymer nanogels have good application prospects due to their good water retention properties and micelle stability properties. At present, a large number of researchers have developed a variety of wound care materials, which are widely used in clinical settings. However, due to the shape of the material or its characteristics, the mechanism of action of many materials has not been studied in detail. How to prepare a new type of wound dressing, which has multiple functions - integrating haemostasis, bacteriostatic, stimulating cell division and differentiation, accelerating tissue healing, moisturising and phlegm, etc., so as to achieve a good evaluation of patients' post-care recovery is. China's long-standing and urgent problem in the medical device market. Therefore, this study used the tetracycline hydrochloride drug doxycycline as an antibiotic drug for nano-modified dressings. Under the theoretical guidance of the interaction between wound healing and pH of microenvironment, a polyethylene glycol (PEG) modified PEG-doxycycline hydrogel nanocomposite dressing was prepared to study the stability of nanoparticles in the dressing. Physical and pH responsiveness, swelling behaviour of composite dressings, and physicochemical properties of drug release behaviour were studied. At the same time, in order to study the effect of the PEG-doxycycline nanocomposite hydrogel on the recovery of wound care in patients, this study applied the composite nano dressing to the clinic. Through the comparative study of patients' quality of life, wound healing, nursing satisfaction and treatment effect, the innovative application of tetracycline hydrochloride in the recovery of wound care of patients under nanotechnology is realised. The results of this study indicate that PEG-doxycycline nanocomposite hydrogel prepared under the guidance of nanotechnology can promote wound healing, shorten hospital stay and reduce complications. At the same time, the use of the dressing can also reduce the work of nursing, alleviate the suffering of the patient, improve the comfort of the patient, and greatly improve the nursing effect and effect on the patient. This has certain promotion and research value for the implementation of continuous nursing methods for patients with chronic wounds, which can be popularised in clinical practice.

Preparation and Properties of Minocycline-Loaded Carboxymethyl Chitosan Gel/Alginate Nonwovens Composite Wound Dressings.

As derivatives from marine natural biomaterials, alginate-based and chitosan-based biomaterials are commonly used in wound dressings. Calcium alginate fiber (CAF) dressings possess excellent absorption and unique gel forming performance, but the low bioactivity limits its application in wound healing. Carboxymethyl chitosan (CM-Chit) has excellent antibacterial activity, but the gel structure with weak mechanical properties restricts its application. In this study, minocycline (Mino)/CM-Chit solution was coated on the surface of plasma treated CAF needle-punched nonwovens, and then Mino loaded CM-Chit gel/CAF nonwovens composite dressings were fabricated by EDC/NHS (1-3-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide) crosslinking. The dressings had a porous composite structure, which allowed them to quickly absorb and store a large number of wound exudates. Skin-like tensile performance allowed the dressings to provide a better healing environment. Antibacterial assay against Escherichia coli and Staphylococcus aureus indicated that the addition of Mino significantly improved the antibacterial activity of the wound dressings. The tight structure of CM-Chit gel prevented the burst release of Mino so that the dressings had antibacterial activity in a certain period of release time. Cell culture assay showed that the dressings had excellent cell biocompatibility. As new functional dressings, the prepared composite dressings had excellent potential in the clinical healing of wounds.