Collagen/chitosan/genipin hydrogel loaded with phycocyanin nanoparticles and ND-336 for diabetic wound healing

Diabetic wound healing remains a healthcare challenge due to the overexpression of matrix metalloproteinase-9 (MMP-9) and the imbalance between angiogenic factors and vascular inhibitory factors. In this study, we developed a nanocomposite injectable collagen/chitosan hydrogel for the treatment of delayed diabetic wound healing, which can promote cell migration to the wound site (through the addition of phycocyanin) and reduce the expression of MMP-9 (through the use of ND-336) to improve the therapeutic effect of diabetic wound healing. Furthermore, different weight ratios of collagen and chitosan hydrogels were prepared to select the hydrogel with proper mechanical properties. In vitro experiments confirmed that all hydrogels have favorable biocompatibility and hemocompatibility. Notably, Gel 2, with a weight ratio of collagen and chitosan at 25:75, was found to have an excellent capability to facilitate cell migration and in vivo studies further proved that Gel 2 nanocomposite hydrogel had the best ability to improve diabetic wound healing by promoting cell migration and decreasing MMP-9 expression. The collagen/chitosan/genipin hydrogel loaded phycocyanin and ND-336 can be harnessed for non-toxic and efficient treatment of wound healing management of diabetes.

Fibronectin in hyperglycaemia and its potential use in the treatment of diabetic foot ulcers: A review

Metabolism of fibronectin, the protein that plays a key role in the healing of wounds, is changed in the patients with diabetes mellitus. Fibronectin can interact with other proteins and proteoglycans and organise them to form the extracellular matrix, the basis of the granulation tissue in healing wounds. However, diabetic foot ulcers (DFUs) suffer from inadequate deposition of this protein. Degradation prevails over fibronectin synthesis in the proteolytic inflammatory environment in the ulcers. Because of the lack of fibronectin in the wound bed, the assembly of the extracellular matrix and the deposition of the granulation tissue cannot be started. A number of methods have been designed that prevents fibronectin degradation, replace lacking fibronectin or support its formation in non-healing wounds in animal models of diabetes. The aim of this article is to review the metabolism of fibronectin in DFUs and to emphasise that it would be useful to pay more attention to fibronectin matrix assembly in the ulcers when laboratory methods are translated to clinical practice.

Advanced Wound Diagnostics: Toward Transforming Wound Care into Precision Medicine

Significance: Nonhealing wounds are an ever-growing global pandemic, with mortality rates and management costs exceeding many common cancers. Although our understanding of the molecular and cellular factors driving wound healing continues to grow, standards for diagnosing and evaluating wounds remain largely subjective and experiential, whereas therapeutic strategies fail to consistently achieve closure and clinicians are challenged to deliver individualized care protocols. There is a need to apply precision medicine practices to wound care by developing evidence-based approaches, which are predictive, prescriptive, and personalized. Recent Advances: Recent developments in "advanced" wound diagnostics, namely biomarkers (proteases, acute phase reactants, volatile emissions, and more) and imaging systems (ultrasound, autofluorescence, spectral imaging, and optical coherence tomography), have begun to revolutionize our understanding of the molecular wound landscape and usher in a modern age of therapeutic strategies. Herein, biomarkers and imaging systems with the greatest evidence to support their potential clinical utility are reviewed. Critical Issues: Although many potential biomarkers have been identified and several imaging systems have been or are being developed, more high-quality randomized controlled trials are necessary to elucidate the currently questionable role that these tools are playing in altering healing dynamics or predicting wound closure within the clinical setting. Future Directions: The literature supports the need for the development of effective point-of-care wound assessment tools, such as a platform diagnostic array that is capable of measuring multiple biomarkers at once. These, along with advances in telemedicine, synthetic biology, and "smart" wearables, will pave the way for the transformation of wound care into a precision medicine. Clinical Trial Registration number: NCT03148977.

Functional Properties of a Purified Reconstituted Bilayer Matrix Design Support Natural Wound Healing Activities

Biomaterial engineering has produced numerous matrices for use in tissue repair, utilizing various materials and processing methods, which can impact the ability of the products to encourage wound healing. Recently, we observed favorable clinical outcomes, using a novel purified reconstituted bilayer matrix (PRBM; Geistlich Derma-Gide) to treat chronic diabetic foot ulcers.

Mimicking the Hierarchical Organization of Natural Collagen: Toward the Development of Ideal Scaffolding Material for Tissue Regeneration

Biological materials found in living organisms, many of which are proteins, feature a complex hierarchical organization. Type I collagen, a fibrous structural protein ubiquitous in the mammalian body, provides a striking example of such a hierarchical material, with peculiar architectural features ranging from the amino acid sequence at the nanoscale (primary structure) up to the assembly of fibrils (quaternary structure) and fibers, with lengths of the order of microns. Collagen plays a dominant role in maintaining the biological and structural integrity of various tissues and organs, such as bone, skin, tendons, blood vessels, and cartilage. Thus, "artificial" collagen-based fibrous assemblies, endowed with appropriate structural properties, represent ideal substrates for the development of devices for tissue engineering applications. In recent years, with the ultimate goal of developing three-dimensional scaffolds with optimal bioactivity able to promote both regeneration and functional recovery of a damaged tissue, numerous studies focused on the capability to finely modulate the scaffold architecture at the microscale and the nanoscale in order to closely mimic the hierarchical features of the extracellular matrix and, in particular, the natural patterning of collagen. All of these studies clearly show that the accurate characterization of the collagen structure at the submolecular and supramolecular levels is pivotal to the understanding of the relationships between the nanostructural/microstructural properties of the fabricated scaffold and its macroscopic performance. Several studies also demonstrate that the selected processing, including any crosslinking and/or sterilization treatments, can strongly affect the architecture of collagen at various length scales. The aim of this review is to highlight the most recent findings on the development of collagen-based scaffolds with optimized properties for tissue engineering. The optimization of the scaffolds is particularly related to the modulation of the collagen architecture, which, in turn, impacts on the achieved bioactivity.

Biological dermal templates with native collagen scaffolds provide guiding ridges for invading cells and may promote structured dermal wound healing

Dermal substitutes are of major importance in treating full thickness skin defects. They come in a variety of materials manufactured into various forms, such as films, hydrocolloids, hydrogels, sponges, membranes, and electrospun micro- and nanofibers. Bioactive dermal substitutes act in wound healing either by delivery of bioactive compounds or by being constructed from materials having endogenous activity. The healing success rate is highly determined by cellular and physiological processes at the host-biomaterial interface during crucial wound healing steps. Hence, it is important to design appropriate wound treatment strategies with the ability to work actively with tissues and cells to enhance healing. Therefore, in this study, we investigated biological dermal templates and their potential to stimulate natural cell adherence, guidance, and morphology. The most pronounced effect was observed in biomaterials with the highest content of native collagen networks. Cell attachment and proliferation were significantly enhanced on native collagen scaffolds. Cell morphology was more asymmetrical on such scaffolds, resembling native in vivo structures. Importantly, considerably lower expression of myofibroblast phenotype was observed on native collagen scaffolds. Our data suggest that this treatment strategy might be beneficial for the wound environment, with the potential to promote improved tissue regeneration and reduce abnormal scar formation.

Evaluation of a superabsorbent wound dressing, patient and clinician perspective: a case series

Objective:

The primary objective of this study was to evaluate the fluid management capabilities of a superabsorbent wound dressing (Zetuvit Plus Silicone), with secondary objectives related to parameters that support whether the dressing enables undisturbed healing.

Method:

This study was an open labelled non-comparative study. Patients included in the study were selected by the clinical investigator(s) according to whether the patient required a dressing for the management of moderately to highly exuding wounds.

Results:

A total of 50 patients were included in the study. Results related to the primary objective demonstrated that the superabsorbent wound dressing was able to absorb all levels of exudate across the range (low to high). At each assessment time point these results show that in 98% of assessments the superabsorbent dressing was rated as ‘very good’ (91%) or ‘good’ (7%) at exudate management. Secondary objectives relating to wound bed preparation, healing and management of pain were also positive. Additionally, at the end of each patient treatment, the dressing's fluid management capabilities were rated overall as ‘excellent’ (100% of cases). There was little pain associated with the wound or at dressing change throughout the study and its flexibility/conformability allowed for comfort and patient satisfaction aligned with increased quality of life. Additionally, inclusion of a silicone adhesive layer allowed painless and atraumatic removal of the dressing, increasing patient comfort, both during wear and at dressing removal, and supported the description of enabling undisturbed wound healing.

Conclusion:

The superabsorbent wound dressing achieved the primary objective relating to wound exudate management in all the assessments undertaken in this study. In addition, the silicone interface allowed for undisturbed healing as evidenced by little or no adherence of the dressing to underlying tissue, preventing damage to periwound skin. Overall, the superabsorbent wound dressing with the addition of the silicone interface could offer advantages over other superabsorbent polymer dressings (that might adhere to the wound surface) or silicone wound dressings (that might not have the absorbent properties of this type of dressing).

Impact of Source and Manufacturing of Collagen Matrices on Fibroblast Cell Growth and Platelet Aggregation

Collagen is a main component of the extracellular matrix. It is often used in medical applications to support tissue regeneration, hemostasis, or wound healing. Due to different sources of collagen, the properties and performance of available products can vary significantly. In this in vitro study, a comparison of seven different collagen matrices derived from bovine, equine, and porcine sources was performed. As performance indicators, the scaffold function for fibroblasts and platelet aggregation were used. We found strong variation in platelet aggregation and fibroblast growth on the different collagen materials. The observed variations could not be attributed to species differences alone, but were highly dependent on differences in the manufacturing process.