Efficacy of alginate-and chitosan-based scaffolds on the healing of diabetic skin wounds in animal experimental models and cell studies: A systematic review

Bioresponsive gingerol-loaded alginate-coated niosomal nanoparticles for targeting intracellular bacteria and cancer cells

Targeting and treating intracellular pathogen infections has been long-standing challenge, particularly in light of the escalating prevalence of antimicrobial resistance. Herein, an optimum formulation of alginate (AL)-coated niosome-based carriers for delivery of herbal extract Gingerol (Gin) was developed to treat intracellular pathogen infections and cancer cells. We used Gin-Nio@AL as a model drug to assess its efficacy against Gram-negative/positive bacteria and breast cancer cell lines. Our investigation affirmed its heightened antibacterial and anticancer properties. The antibacterial activity of Gin-Nio@AL against intracellular Staphylococcus aureus (S. aureus) and pseudomonas aeruginosa (P. aeruginosa) was also tested. In the current study, the niosome nanoparticles containing herbal extract Gingerol were optimized regarding lipid content and Surfactant per Cholesterol molar ratio. The developed formulation provided potential advantages, such as smooth globular surface morphology, small diameter (240.68 nm), pH-sensitive sustained release, and high entrapment efficiency (94.85 %). The release rate of Gin from AL-coated niosomes (Gin-Nio@AL) in physiological and acidic pH is lower than uncoated nanoparticles (Gin-Nio). Besides, the release rate of Gin from niosomal formulations increased in acidic pH. The Gin-Nio@AL demonstrated good antimicrobial activity against S. aureus and P. aeruginosa, and compared to Gin-Nio, the MIC values decreased to 7.82 ± 0.00 and 1.95 ± 0.00 μg/mL, respectively. In addition, the time-kill assay results showed that the developed formulation significantly reduced the number of bacteria in both strains compared to other tested groups. The microtiter data and scanning electron microscope micrography showed that Gin-Nio@AL has a more significant inhibitory effect on biofilm formation than Gin-Nio and Gin. The cell cytotoxicity evaluation showed that Gin-Nio@AL reduced the survival rate of MDA-MB-231 cancer cells to 52.4 % and 45.2 % after 48 h and 72 h, respectively. The elimination of intracellular pathogens was investigated through a breast cancer cell infection in an in vitro model. Gin-Nio@AL exhibited an enhanced and sustained intracellular antibacterial activity against pathogens-infected breast cancer cells compared to other tested formulations. Overall, Gin-Nio@AL enables the triggered release and targeting of intra-extra cellular bacteria and cancer cells and provides a novel and promising candidate for treating intracellular pathogen infections and cancer cells.

The Effect of Chitosan/Alginate/Graphene Oxide Nanocomposites on Proliferation of Mouse Spermatogonial Stem Cells

Male survivors of childhood cancer have been known to be afflicted with azoospermia. To combat this, the isolation and purification of spermatogonial stem cells (SSCs) are crucial. Implementing scaffolds that emulate the extracellular matrix environment is vital for promoting the regeneration and proliferation of SSCs. This research aimed to evaluate the efficiency of nanocomposite scaffolds based on alginate, chitosan, and graphene oxide (GO) in facilitating SSCs proliferation. To analyze the cytotoxicity of the scaffolds, an MTT assay was conducted at 1, 3, and 7 days, and the sample containing 30 µg/mL of GO (ALGCS/GO30) exhibited the most favorable results, indicating its optimal performance. The identity of the cells was confirmed using flow cytometry with C-Kit and GFRα1 markers. The scaffolds were subjected to various analyses to characterize their properties. FTIR was employed to assess the chemical structure, XRD to examine crystallinity, and SEM to visualize the morphology of the scaffolds. To evaluate the proliferation of SSCs, qRT-PCR was used. The study's results demonstrated that the ALGCS/GO30 nanocomposite scaffold exhibited biocompatibility and facilitated the attachment and proliferation of SSCs. Notably, the scaffold displayed a significant increase in proliferation markers compared to the control group, indicating its ability to support SSC growth. The expression level of the PLZF protein was assessed using the Immunocytochemistry method. The observations confirmed the qRT-PCR results, which indicated that the nanocomposite scaffolds had higher levels of PLZF protein expression than scaffolds without GO. The biocompatible ALGCS/GO30 is a promising alternative for promoting SSC proliferation in in vitro applications.

Critical appraisal tools used in systematic reviews of in vitro cell culture studies: A methodological study

Systematic reviews (SRs) of preclinical studies are marked with poor methodological quality. In vitro studies lack assessment tools to improve the quality of preclinical research. This methodological study aimed to identify, collect, and analyze SRs based on cell culture studies to highlight the current appraisal tools utilized to support the development of a validated critical appraisal tool for cell culture in vitro research. SRs, scoping reviews, and meta-analyses that included cell culture studies and used any type of critical appraisal tool were included. Electronic search, study selection, data collection and methodological quality (MQ) assessment tool were realized. Further, statistical analyses regarding possible associations and correlations between MQ and collected data were performed. After the screening process, 82 studies remained for subsequent analysis. A total of 32 different appraisal tools were identified. Approximately 60% of studies adopted pre-structured tools not designed for cell culture studies. The most frequent instruments were SYRCLE (n = 14), OHAT (n = 9), Cochrane Collaboration's tool (n = 7), GRADE (n = 6), CONSORT (n = 5), and ToxRTool (n = 5). The studies were divided into subgroups to perform statistical analyses. A significant association (OR = 5.00, 95% CI = 1.54-16.20, p = 0.008) was found between low MQ and chronic degenerative disorders as topic of SR. Several challenges in collecting information from the included studies led to some modifications related to the previously registered protocol. These results may serve as a basis for further development of a critical appraisal tool for cell culture studies capable of capturing all the essential factors related to preclinical research, therefore enhancing the practice of evidence-based.

The Development of a Polysaccharide-Based Hydrogel Encapsulating Tobramycin-Loaded Gelatine Microspheres as an Antibacterial System

Bacterial infection contributes to the bioburden of wounds, which is an essential factor in determining whether a wound can heal. Wound dressings with antibacterial properties that can promote wound-healing are highly desired for the treatment of chronic wound infections. Herein, we fabricated a simple polysaccharide-based hydrogel dressing encapsulating tobramycin-loaded gelatine microspheres with good antibacterial activity and biocompatibility. We first synthesised long-chain quaternary ammonium salts (QAS) by the reaction of tertiary amines with epichlorohydrin. The amino groups of carboxymethyl chitosan were then conjugated with QAS through the ring-opening reaction and QAS-modified chitosan (CMCS) was obtained. The antibacterial analysis showed that both QAS and CMCS could kill E. coli and S. aureus at relatively low concentrations. QAS with 16 carbon atoms has a MIC of 16 μg/mL for E. coli and 2 μg/mL for S. aureus. A series of formulations of tobramycin-loaded gelatine microspheres (TOB-G) were generated and the best formulation was selected by comparing the characters of the microspheres. The microsphere fabricated by 0.1 mL GTA was selected as the optimal candidate. We then used CMCS, TOB-G, and sodium alginate (SA) to prepare physically crosslinking hydrogels using CaCl2 and investigated the mechanical properties, antibacterial activity, and biocompatibility of the hydrogels. In summary, the hydrogel dressing we produced can be used as an ideal alternative for the management of bacteria-infected wounds.

Efficacy of chitosan in the treatment of chronic skin lesions in a horse: A case report

•

A case of a Gypsy Vanner horse with chronic foreskin lesion is reported.

•

Chronic skin lesions in horses are a diagnostic challenge.

•

Topical application of chitosan favors healing in horses with chronic skin lesions.

•

Chitosan prevents complications in chronic skin lesions in horses.

Consultation was requested for a 7-year-old Gypsy Vanner male horse with a 2-year history of foreskin injury. Upon revision, an ulcer, 153 cm² in size, with yellowish granules was observed; a RESVECH 2.0 evaluation revealed a score of 32/35 points. Medical history confirmed multiple failed deworming, anti-inflammatory, and antibiotic treatments with different topical therapies and recurrence in summer. Laboratory results confirmed elevated total proteins (8.8 g/dL) and globulins (5.5 g/dL), negative bacterial and fungal cultures, as well as negative coproparasitoscopic findings, and finally, identification of stable fly larvae (Stomoxys calcitrans) in the feces. Microscopy showed disorganized collagen, thickened tissue, polymorphonuclear cells, and acanthosis without neoplastic tissue or parasite remains. Debridement was performed and systemic treatment with ivermectin, penicillin, and non-steroidal anti-inflammatory drugs (NSAIDs) continued. In addition, 2% chitosan gel and films were applied to the entire surface of the lesion for 72 hours on 30 occasions; vector control with nets and insecticides was performed. On day 94, there was a 6 cm² surface with involvement of the dermal and epidermal layers, moist epithelial tissue, and diffuse edges, with a RESVECH 2.0 evaluation of 6/35 points. Microscopy showed an intact basement membrane, presence of hair follicles, sweat glands, aligned collagen, and angiogenesis. It was concluded that chronic skin lesions in horses represent a diagnostic challenge, and topical chitosan is an adequate treatment due to its biocompatibility and efficacy, in addition to the functional and cosmetic results in dermal regeneration.

Recent Progress in Development of Dressings Used for Diabetic Wounds with Special Emphasis on Scaffolds

Diabetic wound (DW) is a secondary application of uncontrolled diabetes and affects about 42.2% of diabetics. If the disease is left untreated/uncontrolled, then it may further lead to amputation of organs. In recent years, huge research has been done in the area of wound dressing to have a better maintenance of DW. These include gauze, films, foams or, hydrocolloid-based dressings as well as polysaccharide- and polymer-based dressings. In recent years, scaffolds have played major role as biomaterial for wound dressing due to its tissue regeneration properties as well as fluid absorption capacity. These are three-dimensional polymeric structures formed from polymers that help in tissue rejuvenation. These offer a large surface area to volume ratio to allow cell adhesion and exudate absorbing capacity and antibacterial properties. They also offer a better retention as well as sustained release of drugs that are directly impregnated to the scaffolds or the ones that are loaded in nanocarriers that are impregnated onto scaffolds. The present review comprehensively describes the pathogenesis of DW, various dressings that are used so far for DW, the limitation of currently used wound dressings, role of scaffolds in topical delivery of drugs, materials used for scaffold fabrication, and application of various polymer-based scaffolds for treating DW.

Dose-Effect Relationship of Chitosan and Danshen Combined Injection for Fallopian Tube Recanalization

Objectives: This study examined the dose-effect relationship of chitosan and danshen combined injections on the long-term prevention of fallopian tube re-obstructions, with increased pregnancy rates in infertile women.

Methods: High-performance liquid chromatography was used to determine the content changes of combined chitosan and danshen injection. Two hundred and eighty patients with fallopian tube obstructions were randomly assigned to four groups. Group A (control group, saline), Group B (2 ml chitosan, 4 ml danshen), Group C (2 ml chitosan, 10 ml danshen), and Group D (1 ml chitosan, 10 ml danshen). Injections were administered after tubal recanalization.

Results: The effective constituent of chitosan and danshen injection was stable. Tubal patency rate was 94.2% and 87.3% in Group C after 1 and 3 years, respectively, which was significantly higher than Groups A (38.6%, 31.5%), B (73.5%, 64.1%), and D (68.5%, 50.7%). Intrauterine pregnancy rates were 61.8% and 79.4% in Group C after 1 and 3 years, respectively, and were significantly higher than Groups A (31.8%, 34.8%), B (40.1%, 62.5%), and D (38.5%, 58.5%) (p < 0.05).

Conclusion: Combined Chitosan and danshen injections prevented tubal obstruction and increased pregnancy rates for long periods using an optimal ratio of 1 part chitosan and 5 parts danshen.

CONTRIBUIÇÕES DO ENFERMEIRO NA PESQUISA BÁSICA: MODELO DE FIXAÇÃO DE CURATIVO EM FERIDAS CUTÂNEAS EXCISIONAIS DE CAMUNDONGOS

Objetivo:validar método de fixação de curativos em feridas cutâneas excisionais de camundongos. Método: estudo pré-clínico. Amostra composta por animais da linhagem C57BL/6, que tiveram duas feridas excisionais confeccionadas na região dorsal. Foram avaliados diferentes métodos e produtos, amplamente aceitos na prática clínica, para fixação de curativos no modelo animal. Os desfechos avaliados foram tempo de permanência do curativo e ocorrência de eventos adversos. Resultados: atadura de crepom, fita microporosa e bandagem autoaderente apresentaram menor tempo de permanência quando comparadas ao filme de poliuretano. Esse, por sua vez, variou o tempo quando comparadas diferentes marcas (E, F, G e H) e número de voltas ao redor do corpo do animal. Com 1 volta, o tempo variou de < 24 a 36 horas. Com 2 voltas, as marcas E e G permaneceram 48 e 96 horas, respectivamente, e F e H tempo < 24 horas. Filme da marca G, cortado no tamanho 3 cm x 15 cm, dando 2 voltas no corpo do camundongo, manteve o curativo por 96 horas. A pele permaneceu íntegra, sem evento adverso. Conclusão: foi criado modelo de fixação de curativos para feridas em camundongos com produto disponível no Brasil e compatível com a estrutura copórea do animal.

CONTRIBUTIONS OF NURSES IN BASIC RESEARCH: DRESSING FIXATION MODEL FOR EXCISIONAL CUTANEOUS WOUNDS OF MICE

Objective: validate method of fixation of dressings on excisional cutaneous wounds of mice. Method: preclinical study. Sample made up of animals of the C57BL/6 strain, which had two excision wounds made in the dorsal region. Different methods and products, widely accepted in clinical practice, for fixing dressings in the animal model were evaluated. The evaluated outcomes were the length of stay of the dressing and the occurrence of adverse events. Results: crepe bandage, microporous tape and self adhesive bandage had a shorter residence time when compared to polyurethane film. This, in turn, varied the time when comparing different marks (E, F, G and H) and number of turns around the animal’s body. With 1 lap, the time varied from <24 to 36 hours. With 2 laps, the marks E and G remained 48 and 96 hours, respectively, and F and H time <24 hours. G-brand film, cut to size 3 cm x 15 cm, giving the mouse body 2 turns, kept the dressing for 96 hours. The skin remained intact, with no adverse event. Conclusion: a dressing fixation model for wounds in mice was created with a product available in Brazil and compatible with the animal’s body structure.

Nanotechnology Development for Formulating Essential Oils in Wound Dressing Materials to Promote the Wound-Healing Process: A Review

Wound healing refers to the replacement of damaged tissue through strongly coordinated cellular events. The patient’s condition and different types of wounds complicate the already intricate healing process. Conventional wound dressing materials seem to be insufficient to facilitate and support this mechanism. Nanotechnology could provide the physicochemical properties and specific biological responses needed to promote the healing process. For nanoparticulate dressing design, growing interest has focused on natural biopolymers due to their biocompatibility and good adaptability to technological needs. Polysaccharides are the most common natural biopolymers used for wound-healing materials. In particular, alginate and chitosan polymers exhibit intrinsic antibacterial and anti-inflammatory effects, useful for guaranteeing efficient treatment. Recent studies highlight that several natural plant-derived molecules can influence healing stages. In particular, essential oils show excellent antibacterial, antifungal, antioxidant, and anti-inflammatory properties that can be amplified by combining them with nanotechnological strategies. This review summarizes recent studies concerning essential oils as active secondary compounds in polysaccharide-based wound dressings.