Bacterial cellulose membrane incorporated with silver nanoparticles for wound healing in animal model.

The bacterial cellulose membrane (CM) is a promising biomaterial due to its easy applicability and moist environment. Moreover, nanoscale silver compounds (AgNO3) are synthesized and incorporated into CMs to provide these biomaterials with antimicrobial activity for wound healing. This study aimed to evaluate the cell viability of CM incorporated with nanoscale silver compounds, determine the minimum inhibitory concentration (MIC) for Escherichia coli and Staphylococcus aureus, and its use on in vivo skin lesions. Wistar rats were divided according to treatment: untreated, CM (cellulose membrane), and AgCM (CM incorporated with silver nanoparticles). The euthanasia was performed on the 2nd, 7th, 14th, and 21st days to assess inflammation (myeloperoxidase-neutrophils, N-acetylglucosaminidase-macrophage, IL-1ß, IL-10), oxidative stress (NO-nitric oxide, DCF-H2O2), oxidative damage (carbonyl: membrane's damage; sulfhydryl: membrane's integrity), antioxidants (superoxide dismutase; glutathione), angiogenesis, tissue formation (collagen, TGF-ß1, smooth muscle α-actin, small decorin, and biglycan proteoglycans). The use of AgCM did not show toxicity, but antibacterial effect in vitro. Moreover, in vivo, AgCM provided balanced oxidative action, modulated the inflammatory profile due to the reduction of IL-1ß level and increase in IL-10 level, in addition to increased angiogenesis and collagen formation. The results suggest the use of silver nanoparticles (AgCM) enhanced the CM properties by providing antibacterial properties, modulation the inflammatory phase, and consequently promotes the healing of skin lesions, which can be used clinically to treat injuries.

3D bioprinting complex models of cancer.

Cancer is characterized by the uncontrolled division of cells, resulting in the formation of tumors. The tumor microenvironment (TME) consists of a variety of cell types present within a heterogeneous extracellular matrix (ECM). Current 2D culture methods for mimicking this microenvironment remain limited due to spatial constraints. Many different types of 3D cancer models have been developed in recent years using spheroids/organoids, biomaterial scaffolds, and cancer-on-chip systems. However, these models cannot precisely control the organization of multiple cell types inside of complex architectures. Bioprinted cancer models can incorporate both stromal and cancer cells inside of 3D constructs to generate custom models of this complex disease. 3D bioprinting can generate complex, multicellular, and reproducible constructs where the matrix composition and rigidity are tailored locally to the tumor. These capabilities make 3D bioprinting an attractive method for reproducing the tumor TME found in vivo. Recent advancements in biomaterial-based bioinks enable the generation of 3D bioprinted cancer models that accurately mimic the TM. Here we discuss recent examples of such 3D-bioprinted cancer models, including those of the lungs, prostate, skin, brain, and colon. We then highlight the advantages of using 3D bioprinting compared to other in vitro modeling techniques and detail its limitations.

Microcurrent and Gold Nanoparticles Combined with Hyaluronic Acid Accelerates Wound Healing.

This study aimed to investigate the effects of iontophoresis and hyaluronic acid (HA) combined with a gold nanoparticle (GNP) solution in an excisional wound model. Fifty Wistar rats (n = 10/group) were randomly assigned to the following groups: excisional wound (EW); EW + MC; EW + MC + HA; EW + MC + GNPs; and EW + MC + HA + GNPs. The animals were induced to a circular excision, and treatment started 24 h after injury with microcurrents (300 µA) containing gel with HA (0.9%) and/or GNPs (30 mg/L) in the electrodes (1 mL) for 7 days. The animals were euthanized 12 h after the last treatment application. The results demonstrate a reduction in the levels of pro-inflammatory cytokines (IFNϒ, IL-1ß, TNFα, and IL-6) in the group in which the therapies were combined, and they show increased levels of anti-inflammatory cytokines (IL-4 and IL-10) and growth factors (FGF and TGF-ß) in the EW + MC + HA and EW + MC + HA + GNPs groups. As for the levels of dichlorofluorescein (DCF) and nitrite, as well as oxidative damage (carbonyl and sulfhydryl), they decreased in the combined therapy group when compared to the control group. Regarding antioxidant defense, there was an increase in glutathione (GSH) and a decrease in superoxide dismutase (SOD) in the combined therapy group. A histological analysis showed reduced inflammatory infiltrate in the MC-treated groups and in the combination therapy group. There was an increase in the wound contraction rate in all treated groups when compared to the control group, proving that the proposed therapies are effective in the epithelial healing process. The results of this study demonstrate that the therapies in combination favor the tissue repair process more significantly than the therapies in isolation.

Application of Solidago chilensis and laser improved the repair of burns in diabetic rats.

BACKGROUND: The repair of burns in diabetic patients is a clinical problem. It is relevant to study alternative therapies that can improve the healing process. Our aim was to investigate the effects of Solidago chilensis associated or not with laser on burns in diabetic rats. METHODS: The animals were divided in four groups (n = 30): C- without treatment; S- S. chilensis extract; L-laser irradiated; LS- laser and S. chilensis. In 7, 14 and 21 days samples were collected after the injury to structural, morphometric and molecular analysis. RESULTS: Our results demonstrate the association of S. chilensis and laser reduced the inflammatory infiltrate and favored the angiogenesis. In the groups treated only with laser or with the plant extract showed higher levels of VEGF. The low-level laser therapy (LLLT) promoted higher collagen I and reduction of collagen III. It was also observed higher MMP-2 activation and a decreasing of the active isoform of MMP-9 in the S, L and LS groups. CONCLUSIONS: The treatments improved the repair of burns in diabetic rats, since it reduced the inflammatory infiltrate and favored the collagen organization presenting similar effects in the burn repair of the diabetics.

Experimental models and methods for cutaneous wound healing assessment.

Wound healing studies are intricate, mainly because of the multifaceted nature of the wound environment and the complexity of the healing process, which integrates a variety of cells and repair phases, including inflammation, proliferation, reepithelialization and remodelling. There are a variety of possible preclinical models, such as in mice, rabbits and pigs, which can be used to mimic acute or impaired for example, diabetic and nutrition-related wounds. These can be induced by many different techniques, with excision or incision being the most common. After determining a suitable model for a study, investigators need to select appropriate and reproducible methods that will allow the monitoring of the wound progression over time. The assessment can be performed by non-invasive protocols such as wound tracing, photographic documentation (including image analysis), biophysical techniques and/or by invasive protocols that will require wound biopsies. In this article, we provide an overview of some of the most often needed and used: (a) preclinical/animal models including incisional, excisional, burn and impaired wounds; (b) methods to evaluate the healing progression such as wound healing rate, wound analysis by image, biophysical assessment, histopathological, immunological and biochemical assays. The aim is to help researchers during the design and execution of their wound healing studies.

Hyaluronidase modulates inflammatory response and accelerates the cutaneous wound healing.

Hyaluronidases are enzymes that degrade hyaluronan an important constituent of the extracellular matrix. They have been used as a spreading agent, improving the absorption of drugs and facilitating the subcutaneous infusion of fluids. Here, we investigated the influence of bovine testes hyaluronidase (HYAL) during cutaneous wound healing in in vitro and in vivo assays. We demonstrated in the wound scratch assay that HYAL increased the migration and proliferation of fibroblasts in vitro at low concentration, e.g. 0.1 U HYAL enhanced the cell number by 20%. HYAL presented faster and higher reepithelialization in in vivo full-thickness excisional wounds generated on adult Wistar rats back skin already in the early phase at 2nd day post operatory compared to vehicle-control group. Wound closured area observed in the 16 U and 32 U HYAL treated rats reached 38% and 46% compared to 19% in the controls, respectively. Histological and biochemical analyses supported the clinical observations and showed that HYAL treated wounds exhibited increased granulation tissue, diminished edema formation and regulated the inflammatory response by modulating the release of pro and anti-inflammatory cytokines, growth factor and eicosanoids mediators. Moreover, HYAL increased gene expression of peroxisome proliferator-activated receptors (PPAR) γ and PPAR ß/δ, the collagen content in the early stages of healing processes as well as angiogenesis. Altogether these data revealed that HYAL accelerates wound healing processes and might be beneficial for treating wound disorders.

Self-care competence in the case of Brazilian patients with diabetes mellitus in a multiprofessional educational programme.

AIM: To compare self-care competencies in the physical, cognitive and emotional and motivational dimensions of patients with diabetes mellitus before and after participation in an educational programme. BACKGROUND: Diabetes mellitus is mainly characterised by a dysfunction of glucose metabolism. The growth of diabetes mellitus as a chronic condition requires continuous management and requires health services to implement care strategies. Diabetes education and self-care competence have been recognised over the last few decades as essential for patients with diabetes mellitus to achieve positive treatment results. DESIGN: A prospective, comparative study was used. METHODS: A total of patients with 43 diabetes mellitus participated in this study, before and after a four-month educational programme on diabetes held in Ribeirão Preto, SP, Brazil in 2009. Data were collected through the Scale to Identify diabetes mellitus Patients' Self-Care Competence [Escala para Identificação da Competência do Portador de diabetes mellitus para o Autocuidado] at two points in time: at the beginning (T1) and at the end (T2) of the programme. Linear mixed effects models were used (p<0·05) in the analysis. RESULTS: Statistically significant differences were not found in relation to physical competence in the comparison between T1 and T2. Statistically significant differences were found in the comparison of cognitive and emotional and motivational competencies, respectively, between T1 and T2. CONCLUSION: The scores related to cognitive and emotional and motivational competencies for self-care presented statistically significant differences between T1 and T2. RELEVANCE TO CLINICAL PRACTICE: The educational activities implemented in the educational programme favoured improved cognitive, emotional and motivational competence for the incorporation of positive self-care actions.