自组装纤维支架肽对深Ⅱ度烧伤创面收缩作用的实验研究

目的：探讨纳米短肽对深Ⅱ度烧伤创面的收缩及创面表皮的再生作用。方法：以电力机械烧伤法在雌性SD大鼠背部制造皮肤深Ⅱ度烫伤模型。烧伤后分别以不同生物辅料处理创面,以起到治疗作用。全程记录处理伤口的大体形态学变化。分别在手术后7、10、14、21 d以创面描记及数字图像处理软件系统描述创面生长情况。结果：与对照组生物敷料比较,这种自组装纤维支架肽可以加速缩短焦痂的的形成3～5 d时间,并加速伤口的收缩达20%～30%的水平。结论：自组装纤维支架肽对深度烧伤创面收缩具有促进作用。     

Engineering nanoparticle therapeutics for impaired wound healing in diabetes

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Controlled local drug delivery strategies from chitosan hydrogels for wound healing

Introduction: The main target of tissue engineering is the preparation and application of adequate materials for the design and production of scaffolds, that possess properties promoting cell adhesion, proliferation and differentiation. The use of natural polysaccharides, such as chitosan, to prepare hydrogels for wound healing and controlled drug delivery is a research topic of wide and increasing interest.

Areas covered: This review presents the latest results and challenges in the preparation of chitosan and chitosan-based scaffold/hydrogel for wound healing applications. A detailed overview of their behavior in terms of controlled drug delivery, divided by drug categories, and efficacy was provided and critically discussed.

Expert opinion: The need to establish and exploit the advantages of natural biomaterials in combination with active compounds is playing a pivotal role in the regenerative medicine fields. The challenges posed by the many variables affecting tissue repair and regeneration need to be standardized and adhere to recognized guidelines to improve the quality of evidence in the wound healing process. Currently, different methodologies are followed to prepare innovative scaffold formulations and structures. Innovative technologies such as 3D printing or bio-electrospray are promising to create chitosan-based scaffolds with finely controlled structures with customizable shape porosity and thickness. Chitosan scaffolds could be designed in combination with a variety of polysaccharides or active compounds with selected and reproducible spacial distribution, providing active wound dressing with highly tunable controlled drug delivery.     

An alternative approach to wound healing field; new composite films from natural polymers for mupirocin dermal delivery

In this study, novel adhesive films were prepared for Mupirocin dermal delivery. Natural polymers as chitosan, sodium alginate and carbopol were used for films development to evaluate possible interactions and drug release properties. Solvent evaporation method was used for films preparation. Preliminary studies involved FT-IR spectroscopy and Scanning Electron Microscopy to specify interactions and morphology. Thickness, tensile strength and water uptake in phosphate buffer saline were evaluated whereas in vitro release studies were also performed. In vitro drug release studies demonstrated that mupirocin release was improved. Ex vivo bioadhesion and permeation studies using Balb-c mice were performed to check the suitability of the films. Antimicrobial ability was evaluated by agar well diffusion tests. Finally, excisional wound model applied to test the wound healing effect and evaluated macroscopic and histopathologically. One formulation was found more effective compared to the market product for wound healing at Balb-c mice.     

Potential benefits of using chitosan and silk fibroin topical hydrogel for managing wound healing and coagulation

Background & ObjectivesThe intricate process of wound healing involves replacing the cellular or tissue structure that has been destroyed. In recent years various wound dressings were launched but reported several limitations. The topical gel preparations are intended for certain skin wound conditions for local action. Chitosan-based hemostatic materials are the most effective in halting acute hemorrhage, and naturally occurring silk fibroin is widely utilized for tissue regeneration. So, this study was conducted to evaluate the potential of chitosan hydrogel(CHI-HYD) and chitosan silk fibroin hydrogel (CHI-SF-HYD) on blood clotting and wound healing.MethodsHydrogel was prepared using various concentrations of silk fibroin with guar gum as a gelling agent. The optimized formulations were evaluated for visual appearance, Fourier transforms infrared spectroscopy (FT-IR), pH, spreadability, viscosity, antimicrobial activity, HR-TEM analysis, ex vivo skin permeation, skin irritation, stability studies, and in vivo studies by using adult male Wistar albino rats.ResultsBased on the outcome of FT-IR, no chemical interaction between the components was noticed. The developed hydrogels exhibited a viscosity of 79.2 ± 4.2 Pa.s (CHI-HYD), 79.8 ± 3.8 Pa.s (CHI-SF-HYD), and pH of 5.87 ± 0.2 (CHI-HYD), 5.96 ± 0.1 (CHI-SF-HYD). The prepared hydrogels were sterile and non-irritant to the skin. The in vivo study outcomes show that the CHI-SF-HYD treated group has significantly shortened the span of tissue reformation than other groups. This demonstrated that the CHI-SF-HYD could consequently accelerate the regeneration of the damaged area.Interpretation & ConclusionOverall, the positive outcomes revealed improved blood coagulation and re-epithelialization. This indicates that the CHI-SF-HYD could be used to develop novel wound-healing devices.     

Chitosan and its derivatives as vehicles for drug delivery

Abstract

Chitosan and its derivatives as vehicles for drug delivery can achieve the purpose of sustained release and controlled release for drugs, improve the stability of drugs, and reduce adverse drug reactions. So, the bioavailability of drugs can be enhanced. Therefore, chitosan and its derivatives have become a hotspot in the field of drug delivery. Their characteristics as drug delivery vectors were introduced, the types and applications were summarized. The development direction of chitosan and its derivatives in this field was also forecasted.     

Chitosan as a Novel Nasal Delivery System for Peptide Drugs

A nasal solution formulation of the cationic material chitosan was shown to greatly enhance the absorption of insulin across the nasal mucosa of rat and sheep. The absorption promoting effect was concentration dependent with the optimal efficacy obtained for concentrations higher than 0.2% and 0.5% in rats and sheep, respectively. The absorption promoting effect was reversible with time in a pulse-chase study. Histological examination of the nasal mucosa of rats exposed to a chitosan solution for 60 minutes showed little change.     

Hyaluronic acid and chitosan-based nanosystems: a new dressing generation for wound care

ABSTRACT

Introduction: The main goal in the management of chronic wounds is the development of multifunctional dressings able to promote a rapid recovery of skin structure and function, improving patient compliance.

Areas covered: This review discusses the use of nanosystems, based on hyaluronic acid and chitosan or their derivatives for the local treatment of chronic wounds. The bioactive properties of both polysaccharides will be described, as well as the results obtained in the last decade by the in vitro and in vivo evaluation of the wound healing properties of nanosystems based on such polymers.

Expert opinion: In the last decades, there has been a progressive change in the local treatments of chronic wounds: traditional inert dressings have been replaced by more effective bioactive ones, based on biopolymers taking part in wound healing and able to release the loaded active agents in a controlled way. With the advance of nanotechnologies, the scenario has further changed: nanosystems, characterized by a large area-to-volume ratio, show an improved interaction with the biological substrates, amplifying the activity of the constituent biopolymers. In the coming years, a deeper insight into wound healing mechanisms and the development of new techniques for nanosystem manufacturing will results in the design of new scaffolds with improved performance.     

Synthesis and Evaluation of Boronated Chitosan as a Mucoadhesive Polymer for Intravesical Drug Delivery

This work reports the synthesis of boronated chitosan by reacting it with 4-carboxyphenylboronic acid to improve its mucoadhesive properties. Three products with differing extent of boronate conjugation were synthesized and characterized using ¹H NMR, FT-IR, and UV-Vis spectroscopy, and the potential of these polymers to extend the residence time of loaded model drug in the bladder was investigated. ¹H NMR and ninhydrin test were used to evaluate the extent of chitosan modification. Mucoadhesive properties were evaluated using ex vivo flow-through technique on porcine bladder mucosal tissue combined with fluorescent microscopy, where fluorescein sodium was used as a model drug. The mucoadhesive properties of these polymers on porcine bladder mucosa were also studied using tensile test. There was good correlation in the mucoadhesive profiles of the polymers using the flow through and tensile techniques. The degree of chitosan modification had a remarkable influence on their mucoadhesive behavior, and greater mucoadhesion was observed with increased degree of boronation. These chitosan derivatives have the potential as intravesical drug delivery systems to improve bladder therapy.     

Biologically active Chitosan/ZnO/Acalypha indica leaf extract biocomposite: An investigation of antibacterial,cell proliferation and cell migration aptitude for wound healing application

A biocomposite composed of Chitosan (Cs), Zinc oxide (ZnO), Acalypha indica (AI) was fabricated by simple chemical precipitation method. The achieved biocomposite was characterized by Fourier Transmission Infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), Scanning electron microscope (SEM) with Energy dispersive X-ray analysis spectroscopy (EDAX) and Transmission electron microscope (TEM). The phytochemical constituents in the AI leaf extract were also studied by Gas chromatography mass spectrometer (GC-MS) analysis. The anti-inflammatory and antioxidant studies were studied using Diclofenac sodium and ascorbic acid as standard by Fetal bovine serum denaturation and (2,2-diphenyl-1-picryl-hydrazyl-hydrate) DPPH radical scavenging method. The effective bactericidal action of the composite was evaluated against both gram-negative, gram-positive bacteria such as Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus). The hemolysis activity was studied using Triton x 100 as negative and Phosphate buffer solution (PBS) as positive control. The biocompatibility nature was evaluated by the MTT (3- (4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) MTT assay and Fluorescence staining method using mouse fibroblast cells (L929). Additionally, the in-vitro wound healing potential was also assessed by scratch wound assay with L929 mouse fibroblast cells. Hence, these obtained results suggest that the Cs/ZnO/AI biocomposite can act as a suitable candidate in wound care applications.     

Development and characterization of a superabsorbing hydrogel film containing Ulmus davidiana var. Japonica root bark and pullulan for skin wound healing

Ulmus davidiana var. japonica (UD) has widely been used in Korean traditional medicine for the treatment of various types of diseases including inflammation and skin wounds. The UD root bark powders possess gelling activity with an excellent capacity for absorbing water. This distinct property could make the UD root bark powders to be a great material for manufacturing a gel film specifically for the healing of large and highly exudating wounds (e.g., pressure sores and diabetic ulcers). In this research, we separated the UD root bark powder into 4 different samples based on their sizes and then tested their water absorption capacity and flowability. Based on these results, 75–150 μm sized and below 75 μm sized samples of UD root bark powders were chosen, and UD gel films were prepared. The UD gel films showed good thermal stability and mechanically improved properties compared with pullulan only gel film with excellent swelling capacity and favorable skin adhesiveness. Further, in the animal studies with the skin wound mice model, the UD gel films exhibited significant therapeutic effects on accelerating wound closure and dermal regeneration. Overall, this study demonstrated the applicability of UD root bark powders for hydrogel wound dressing materials, and the potential of UD gel films to be superior wound dressings to currently available ones.     

In-vitro and in-vivo cytotoxicity and efficacy evaluation of novel glycyl-glycine and alanyl-alanine conjugates of chitosan and trimethyl chitosan nano-particles as carriers for oral insulin delivery

Purpose

The aim of this research work was to explore the possibility of providing multifunctional oral insulin delivery system by conjugating several types of dipeptides on chitosan and trimethyl chitosan to be used as drug carriers.

Local anesthetic lidocaine-encapsulated polymyxin–chitosan nanoparticles delivery for wound healing: in vitro and in vivo tissue regeneration

In relieving local pains, lidocaine, one of ester-type local anesthetics, has been used. To develop the lidocaine membranes of enhanced local anesthetic effects, we have designed to establish the composition of wound dressings based on lidocaine chloride (LCH) (anesthetic drug)-loaded chitosan (CS)/polymyxin B sulfate (PMB). The LCH membranes (LCH-CS/PMB) was fabricated by the LCH oxide solutions within the CS/PMB matrix. The influences of different experimental limitations on CS/PMB membrane formations were examined. The double membrane particle sizes were evaluated by scanning electron microscopy (HR-SEM). Additionally, antibacterial efficacy was developed for gram-positive and negative microorganisms. Moreover, we examined in vivo healing of skin wounds formed in mouse models over 16 days. In contrast to the untreated wounds, rapid healing was perceived in the LCH-CS/PMB-treated wound with less damaging. These findings indicate that LCH-CS/PMB-based bandaging materials could be a potential innovative biomaterial for tissue repair and regeneration for wound healing applications in an animal model.