Combination therapy of oxidised regenerated cellulose/collagen/silver dressings with negative pressure wound therapy for coverage of exposed critical structures in complex lower-extremity wounds

Functionalised Sodium-Carboxymethylcellulose-Collagen Bioactive Bilayer as an Acellular Skin Substitute for Future Use in Diabetic Wound Management: The Evaluation of Physicochemical, Cell Viability, and Antibacterial Effects

The wound healing mechanism is dynamic and well-orchestrated; yet, it is a complicated process. The hallmark of wound healing is to promote wound regeneration in less time without invading skin pathogens at the injury site. This study developed a sodium-carboxymethylcellulose (Na-CMC) bilayer scaffold that was later integrated with silver nanoparticles/graphene quantum dot nanoparticles (AgNPs/GQDs) as an acellular skin substitute for future use in diabetic wounds. The bilayer scaffold was prepared by layering the Na-CMC gauze onto the ovine tendon collagen type 1 (OTC-1). The bilayer scaffold was post-crosslinked with 0.1% (w/v) genipin (GNP) as a natural crosslinking agent. The physical and chemical characteristics of the bilayer scaffold were evaluated. The results demonstrate that crosslinked (CL) groups exhibited a high-water absorption capacity (>1000%) and an ideal water vapour evaporation rate (2000 g/m2 h) with a lower biodegradation rate and good hydrophilicity, compression, resilience, and porosity than the non-crosslinked (NC) groups. The minimum inhibitory concentration (MIC) of AgNPs/GQDs presented some bactericidal effects against Gram-positive and Gram-negative bacteria. The cytotoxicity tests on bilayer scaffolds demonstrated good cell viability for human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs). Therefore, the Na-CMC bilayer scaffold could be a potential candidate for future diabetic wound care.

Comparative Effectiveness of Negative Pressure Wound Therapy with and Without Oxidized Regenerated Cellulose/Collagen/Silver-ORC Dressing

Objective: Negative pressure wound therapy (NPWT) and oxidized regenerated cellulose (ORC)/collagen/silver-ORC (OCSO) dressings have individually demonstrated effectiveness in supporting wound healing, but few studies have examined their combined use. This retrospective data analysis compared wound outcomes following outpatient NPWT with and without OCSO dressings. Approach: A search of deidentified records from the U.S. Wound Registry resulted in 485 cases of wounds managed with NPWT with OCSO dressings. A matched cohort of patients who received NPWT without any collagen dressing (n = 485) was created using propensity scoring. For patients in the NPWT + OCSO group, OCSO was applied topically on or after the day of NPWT initiation and stopped on or before the day of NPWT termination. Results: Wounds managed with NPWT + OCSO were significantly more likely to improve and/or heal compared with wounds that received NPWT alone (p = 0.00029). The relative wound area reduction was 40% for patients receiving NPWT + OCSO, compared with 9% for patients receiving only NPWT (p = 0.0099). The median time to achieve 75-100% granulation coverage with no measurable wound depth was shorter by 8 days with NPWT + OCSO in all wound types (p = 0.00034), and by 14 days in surgical wounds (p = 0.0010), than with NPWT alone. Innovation: This is the first study examining the clinical outcomes associated with the integration of NPWT and OCSO dressings compared with the use of NPWT alone. These data support the novel practice of applying NPWT concurrently with OCSO dressings. Conclusion: This retrospective comparative analysis using real-world data demonstrated improved healing outcomes with integrated use of NPWT with OCSO dressings versus NPWT alone.

Bioactive Dressing: A New Algorithm in Wound Healing

Wound management presents a significant global challenge, necessitating a comprehensive understanding of wound care products and clinical expertise in selecting dressings. Bioactive dressings (BD) represent a diverse category of dressings, capable of influencing wound healing through various mechanisms. These dressings, including honey, hyaluronic acid, collagen, alginates, and polymers enriched with polyhexamethylene biguanide, chitin, and chitosan derivatives, create a conducive environment for healing, promoting moisture balance, pH regulation, oxygen permeability, and fluid management. Interactive dressings further enhance targeted action by serving as substrates for bioactive agents. The continuous evolution of BDs, with new products introduced annually, underscores the need for updated knowledge in wound care. To facilitate dressing selection, a practical algorithm considers wound exudate, infection probability, and bleeding, guiding clinicians through the process. This algorithm aims to optimize wound care by ensuring the appropriate selection of BDs tailored to individual patient needs, ultimately improving outcomes in wound management.

Mini-Review: Tendon-Exposed Wound Treatments

BACKGROUND

Tendon-exposed wounds are complex injuries with challenging reconstructions and no unified treatment mode. Furthermore, insufficient tissue volume and blood circulation disorders affect healing, which increases pain for the patient and affects their families and caretakers.

REVIEW

As modern medicine advances, considerable progress has been made in understanding and treating tendon-exposed wounds, and current research encompasses both macro-and micro-studies. Additionally, new treatment methods have emerged alongside the classic surgical methods, such as new dressing therapies, vacuum sealing drainage combination therapy, platelet-rich plasma therapy, and live-cell bioengineering.

CONCLUSIONS

This review summarizes the latest treatment methods for tendon-exposed wounds to provide ideas and improve their treatment.

Influence of advanced wound matrices on observed vacuum pressure during simulated negative pressure wound therapy

Biomaterials and negative pressure wound therapy (NPWT) are treatment modalities regularly used together to accelerate soft-tissue regeneration. This study evaluated the impact of the design and composition of commercially available collagen-based matrices on the observed vacuum pressure delivered under NPWT using a custom test apparatus. Specifically, testing compared the effect of the commercial products; ovine forestomach matrix (OFM), collagen/oxidized regenerated cellulose (collagen/ORC) and a collagen-based dressing (CWD) on the observed vacuum pressure. OFM resulted in an ∼50% reduction in the observed target vacuum pressure at 75 mmHg and 125 mmHg, however, this effect was mitigated to a ∼0% reduction when fenestrations were introduced into the matrix. Both collagen/ORC and CWD reduced the observed vacuum pressure at 125 mmHg (∼15% and ∼50%, respectively), and this was more dramatic when a lower vacuum pressure of 75 mmHg was delivered (∼20% and ∼75%, respectively). The reduced performance of the reconstituted collagen products is thought to result from the gelling properties of these products that may cause occlusion of the delivered vacuum to the wound bed. These findings highlight the importance of in vitro testing to establish the impact of adjunctive therapies on NPWT, where effective delivery of vacuum pressure is paramount to the efficacy of this therapy.

Use of oxidised regenerated cellulose/collagen dressings versus standard of care over multiple wound types: A systematic review and meta-analysis

Oxidised regenerated cellulose (ORC)/collagen dressings help maintain physiologically moist wound environments conducive to wound healing. While evidence supporting ORC/collagen dressing use exists, comprehensive assessment is needed. This systematic review/meta-analysis evaluated the performance of ORC/collagen dressings compared with standard dressings. A systematic literature search was performed using PUBMED, EMBASE, and QUOSA Virtual Library. Published studies and conference abstracts were assessed between 1 January 1996 and 27 July 2020. Comparative studies in English completed by 31 December 2019, with a study population ≥10 were included. Patient demographics, wound healing, and protease concentrations were extracted. A random-effect model was used to assess the effect of ORC/collagen dressings. Twenty studies were included following removal of duplicates and articles not meeting inclusion criteria. A statistically significant effect in favour of ORC/collagen dressings was found for wound closure (P = 0.027) and percent wound area reduction (P = 0.006). Inconclusive evidence or limited reporting prevented assessment of time to complete healing, days of therapy, number of dressing applications, pain, matrix metalloproteinase, elastase, plasmin, and gelatinase concentration. Statistically significant increase in wound closure rates and percent wound area reduction were observed in patients receiving ORC/collagen dressings compared with standard dressings in this systematic review/meta-analysis.

Combination therapy of oxidised regenerated cellulose/collagen/silver dressings with negative pressure wound therapy for coverage of exposed critical structures in complex lower-extremity wounds

Complex wounds with exposed critical structures such as tendon and bone are a conundrum in wound management, especially in the setting where the patient is not a suitable candidate for flap surgery. While the individual use of negative pressure wound therapy (NPWT) and oxidised regenerated cellulose (ORC)/collagen/silver (PROMOGRAN PRISMA) dressing has been described in the literature, there are little data on the efficacy of their combined use. In this study, we describe a novel technique of combining the use of NPWT and ORC/collagen/silver dressings to manage complex wound beds as an alternative management option for patients not suitable for reconstructive flap surgery. This technique was performed in a series of 37 patients with complex lower-extremity wounds that were not healing with conventional NPWT alone. All patients had open wounds with exposed critical structures that were difficult to manage, such as exposed tendon, bone, deep crevices, and joint. Successful coverage of exposed critical structures was achieved in 89% of patients, and coverage was achieved within 28 days of combination therapy in 82% of these patients, without any complications. The novel technique of combining ORC/collagen/silver dressing and NPWT provides a useful option in the armamentarium of a reconstructive surgeon dealing with difficult complex lower-extremity wounds.