A bioreactor for studying negative pressure wound therapy on skin grafts

Exploring an Innovative Approach: Integrating Negative-Pressure Wound Therapy with Silver Nanoparticle Dressings in Skin Graft Procedures

BACKGROUND

Skin grafting is a helpful instrument in a plastic surgeon's arsenal. Several types of dressings were designed to facilitate the process of graft integration. Negative-pressure wound therapy is a proven dressing method, enhancing graft survival through several mechanisms: aspiration of secretions, stimulation of neoangiogenesis, and promotion of an anti-inflammatory environment. Silver nanoparticle dressings also bring multiple benefits by bearing an antimicrobial effect and providing a humid medium, which are favorable for epithelialization. The combination of NPWT (negative-pressure wound therapy) with AgNPs (silver nanoparticles) has not been widely studied.

MATERIALS AND METHODS

This study aimed to compare the outcomes of silver nanoparticle sheets with the combination of negative-pressure wound therapy and silver nanoparticle dressings. We conducted a comparative prospective study on 80 patients admitted to the Plastic Surgery Department of "Prof. Dr. Agrippa Ionescu" Emergency Clinical Hospital between 1st of January 2020 and 31st of December 2022. The study population was randomized to receive either silver nanoparticle dressings or negative-pressure wound therapy (NPWT) combined with silver nanoparticle dressings. Various parameters were monitored, including patient comorbidities and graft-related data such as defect etiology, graft integration, and graft size. Dressings were changed, and graft status was evaluated at 7, 10, and 14 days postoperatively. Additionally, baseline C-reactive protein (CRP) levels were measured before surgery and 7, 10, and 14 days postoperatively.

RESULTS

The study demonstrated an enhanced integration of skin grafts at all evaluation stages when employing NPWT combined with AgNPs, particularly evident 10 days post operation. Significant variations in graft integration were also observed based on factors such as diabetes, cardiovascular disease, graft size, or the origin of the grafted defect. Moreover, dynamic C-reactive protein monitoring showed a statistically significant decrease in CRP levels 10 days post operation among patients treated with NPWT in conjunction with silver dressing, consistent with the nearly complete integration of skin grafts at this evaluation threshold.

CONCLUSION

Several factors influence the postoperative evolution of split-skin grafts. Postoperative dressings target local factors to enhance graft integration further. Our research demonstrated that the innovative combination of NPWT-assisted dressings, complemented by a silver nanoparticle sheet, resulted in improved benefits for graft integration and the alleviation of systemic inflammation.

Innervation of an Ultrasound-Mediated PVDF-TrFE Scaffold for Skin-Tissue Engineering

In this work, electrospun polyvinylidene-trifluoroethylene (PVDF-TrFE) was utilized for its biocompatibility, mechanics, and piezoelectric properties to promote Schwann cell (SC) elongation and sensory neuron (SN) extension. PVDF-TrFE electrospun scaffolds were characterized over a variety of electrospinning parameters (1, 2, and 3 h aligned and unaligned electrospun fibers) to determine ideal thickness, porosity, and tensile strength for use as an engineered skin tissue. PVDF-TrFE was electrically activated through mechanical deformation using low-intensity pulsed ultrasound (LIPUS) waves as a non-invasive means to trigger piezoelectric properties of the scaffold and deliver electric potential to cells. Using this therapeutic modality, neurite integration in tissue-engineered skin substitutes (TESSs) was quantified including neurite alignment, elongation, and vertical perforation into PVDF-TrFE scaffolds. Results show LIPUS stimulation promoted cell alignment on aligned scaffolds. Further, stimulation significantly increased SC elongation and SN extension separately and in coculture on aligned scaffolds but significantly decreased elongation and extension on unaligned scaffolds. This was also seen in cell perforation depth analysis into scaffolds which indicated LIPUS enhanced perforation of SCs, SNs, and cocultures on scaffolds. Taken together, this work demonstrates the immense potential for non-invasive electric stimulation of an in vitro tissue-engineered-skin model.

Efficacy of prophylactic negative pressure wound therapy after open ventral hernia repair: a systematic review meta-analysis

INTRODUCTION

The susceptibility to surgical site occurrence (SSO) is high following ventral hernia repair (VHR) surgery. SSO severely increases the physical and mental burden on patients. The main purpose of this review was to analyze the efficacy of negative pressure wound therapy (NPWT) after open VHR(OVHR) and explore benefits to patients.

METHODS

The Cochrane Library, PubMed, and Embase databases were searched from the date of establishment to 15 October 2022. All randomized controlled trials and retrospective cohort studies comparing NPWT with standard dressings after OVHR were included. The Revman 5.4 software recommended by Cochrane and the STATA16 software were used in this meta-analysis.

RESULTS

Fifteen studies (involving 1666 patients) were identified and included in the meta-analysis, with 821 patients receiving NPWT. Overall, the incidence rate of SSO in the NPWT group was lower compared to the control group (odds ratio [OR] = 0.44; 95% confidence interval [CI] = 0.21-0.93; I2 = 86%; P = 0.03). The occurrence rate of surgical site infection (SSI; OR = 0.51; 95% CI = 0.38-0.68, P < 0.001), wound dehiscence (OR = 0.64; 95% CI = 0. 43-0.96; P = 0.03), and hernia recurrence (OR = 0.51; 95% CI = 0.28-0.91, P = 0.02) was also lowered. There was no significant difference in seroma (OR = 0.76; 95% CI = 0.54-1.06; P = 0.11), hematoma (OR = 0.53; 95% CI = 0.25-1.11; P = 0.09), or skin necrosis (OR = 0.83; 95% CI = 0.47-1.46; P = 0.52).

CONCLUSION

NPWT can effectively decrease the occurrence of SSO, SSI wound dehiscence and hernia recurrence and should be considered following OVHR.

Roles of negative pressure wound therapy for scar revision

The purpose of this study is to review the research progress of negative pressure wound therapy (NPWT) for scar revision and discuss the prospects of its further study and application. The domestic and foreign literatures on NPWT for scar revision were reviewed. The mechanism and application were summarized. NPWT improves microcirculation and lymphatic flow and stimulates the growth of granulation tissues in addition to draining secretions and necrotic tissue. As a significant clinical therapy in scar revision, NPWT reduces tension, fixes graft, and improves wound bed. In the field of scar revision, NPWT has been increasingly used as an innovative and constantly improving technology.