Physiology of wound healing and surgical wound care

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

Biodegradable Silk Fibroin Matrices for Wound Closure in a Human 3D Ex Vivo Approach

In this study, the potential of silk fibroin biomaterials for enhancing wound healing is explored, focusing on their integration into a human 3D ex vivo wound model derived from abdominoplasties. For this purpose, cast silk fibroin membranes and electrospun nonwoven matrices from Bombyx mori silk cocoons were compared to untreated controls over 20 days. Keratinocyte behavior and wound healing were analyzed qualitatively and quantitatively by histomorphometric and immune histochemical methods (HE, Ki67, TUNEL). Findings reveal rapid keratinocyte proliferation on both silk fibroin membrane and nonwoven matrices, along with enhanced infiltration in the matrix, suggesting improved early wound closure. Silk fibroin membranes exhibited a significantly improved early regeneration, followed by nonwoven matrices (p < 0.05) compared to untreated wounds, resulting in the formation of multi-layered epidermal structures with complete regeneration. Overall, the materials demonstrated excellent biocompatibility, supporting cell activity with no signs of increased apoptosis or early degradation. These results underscore silk fibroin's potential in clinical wound care, particularly in tissue integration and re-epithelialization, offering valuable insights for advanced and-as a result of the electrospinning technique-individual wound care development. Furthermore, the use of an ex vivo wound model appears to be a viable option for pre-clinical testing.

Evaluating a promising methylcellulose hydrogel for enhanced diabetic foot ulcer therapy through comprehensive preclinical studies

The present research focuses on formulating and evaluating hydrogels modified with crosslinking agents using methylcellulose to treat diabetic foot ulcers (DFU). Methylcellulose hydrogels are prepared and characterized for their crosslinking capacity through FTIR and degradation studies. The optimized hydrogel is further assessed for viscosity, gel strength, contact angle, in-vitro biodegradation, water-vapor transmission rate, anti-bacterial activity, and in-vivo efficacy. The results demonstrate that the developed hydrogel exhibits promising properties for DFU treatment, including increased wound healing percentage, improved ulcer morphology, reduced levels of proinflammatory cytokines, and enhanced tissue characteristics. These findings suggest that the novel hydrogel composition could serve as a viable alternative to existing dressings for DFU management.

Blubber biopsy in common bottlenose dolphins using a novel biopsy puncher: Evaluation of the impact on living individuals and possibility of applications in cetacean research

Biopsy has recently become a preferred protocol for sampling the skin and blubber of many cetacean species, although it is desirable to collect as minimally invasive as possible. Here, the effect of biopsy sampling on the captive common bottlenose dolphins was evaluated by analyzing the process of wound healing and changes in hematological and blood biochemical parameters after biopsy using a puncher developed to collect up to the inner layer of the dolphin blubber. Results showed that the wounds caused by biopsy were closed in as early as 1 day and completely covered with the epidermis within 5-11 days. Blood fibrinogen, which generally increases due to a wound-induced inflammatory response or activation of the coagulation system, was significantly elevated after the biopsy indicating ongoing tissue repair, while other parameters did not exhibit significant differences. Furthermore, histological observation and RNA extraction of samples were performed to investigate the versatility of this method to cetacean research. Histological examination revealed three distinct layers of the blubber in the biopsy samples. Moreover, total RNA extracted from biopsy samples exhibited sufficient quality and quantity for gene expression analyses. Overall, the puncher utilized in our study represents a valuable and minimally invasive tool for investigating various aspects of small cetacean studies.

Key performance indicators to inform evaluation of wound care programmes for people with complex wounds: a protocol for systematic review

OBJECTIVE

The objective of the systematic review is to examine and summarise the available evidence in the literature of the use of key performance indicators (KPIs) to inform evaluation of wound care programmes and services for people with hard-to-heal (complex) wounds. The need for wound care is expected to grow with the continued ageing of the population and the resulting increased development of chronic conditions. This expected increase necessitates improvement of wound care programmes and services and their ability to deliver quality, evidence-based and cost-effective practice. The current literature lacks a systematic assessment of KPIs to inform evaluation of wound care services and programmes across various settings, and how the KPIs are used to improve the quality of wound care and achieve desired outcomes. This protocol sets out how the systemtic review will be undertaken.

METHOD

Primary studies will be screened from databases such as MEDLINE, CINAHL and Scopus, with unpublished studies and grey literature retrieved from Google Scholar and ProQuest Dissertations and Theses. The study titles and abstracts will be screened by two independent reviewers, using Covidence systematic review software to ensure they meet the inclusion criteria, who will then proceed with data extraction of the full-text using the standardised data extraction instrument. The reference lists of all studies selected for critical appraisal will be screened for additional publications. The two independent reviewers will critically appraise all studies undergoing full-text data extraction using the appropriate checklist from JBI SUMARI. At all stages, differences between reviewers will be resolved through discussion, with adjudication by a third, independent reviewer.

RESULTS

Data points will be analysed with descriptive statistics and grouped, based on programme characteristics and publication status. Grey literature and peer-reviewed publications will form separate analyses. To answer review questions, the data will be summarised in a narrative format. A meta-analysis is not planned. At the time of writing, this protocol has been implemented up to the preliminary literature search.

CONCLUSION

This review will address a current literature gap and systematically identify KPIs in wound care, allowing for programmes to evaluate their quality of care and improve their services in a methodical manner.

Knowledge, attitude and practices towards surgical wound care and healing among the public in the Jazan Region, Saudi Arabia

The purpose of this research was to evaluate how much the people in the Jazan region know about the care and healing of surgical wounds. Proper care of surgical wounds is very important to achieve the best treatment outcomes and to avoid negative consequences. However, factors like obesity, diabetes, and certain medications can impair wound healing, with surgical site infections being a major problem in the healthcare system. Therefore, this study aimed to determine public awareness and perceptions of surgical wound care to help improve education and raise awareness of the importance of proper wound care for better results. We run an observational cross-sectional study among adults above 18 years in the Jazan region. An online self-administered questionnaire was used in the collection of data. Simple random sampling was the used technique and 384 participants were calculated. The study used Statistical Package for the Social Sciences (SPSS) for data analysis and employed descriptive statistics, independent t test, Analysis of Variance (ANOVA), Pearson's correlation, and multivariate logistic regression to identify factors associated with knowledge of surgical site infection and wound care. This study analyzed 599 participants' knowledge, attitude, and practice about surgical site infection and wound management. While participants had a strong general understanding of surgical wounds, only 17% had a high degree of knowledge about surgical site infection and wound management. Medical students had the highest degree of knowledge, and being a medical student was the only significant predictor of having a high level of knowledge about surgical site infection (SSI) and wound care. The study emphasizes the necessity of enhanced patient education and investment in medical education quality. The participants in this study had high overall knowledge regarding surgical wounds but lacked particular knowledge concerning surgical site infection and wound management. Medical education was discovered to be a strong predictor of having a high level of knowledge about surgical site infection and wound management. Healthcare professionals should take the lead in giving accurate and reliable information regarding wound care techniques to patients, and legislators should invest in enhancing medical education quality.

Impact of moist wound dressing on wound healing time: A meta-analysis

Among the assortment of available dressings aimed at promoting wound healing, moist dressings have gained significant popularity because of their ability to create an optimal environment for wound recovery. This meta-analysis seeks to compare the effects of moist dressing versus gauze dressing on wound healing time. A comprehensive literature search was conducted, encompassing publications up until April 1, 2023, across multiple databases including PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Cochrane Library. Stringent criteria were used to determine study inclusion and evaluate methodological quality. Statistical analyses were performed utilizing Stata 17.0. A total of 13 articles, encompassing 866 participants, were included in the analysis. The findings indicate that moist dressing surpasses gauze dressing in terms of wound healing time (standard mean difference [SMD] -2.50, 95% confidence interval [CI] -3.35 to -1.66, p < 0.01; I2  = 97.24%), wound site infection rate (odds ratio [OR] 0.30, 95% CI 0.17 to 0.54, p < 0.01; I2  = 39.91%), dressing change times (SMD -3.65, 95% CI -5.34 to -1.97, p < 0.01; I2  = 96.48%), and cost (SMD -2.66, 95% CI -4.24 to -1.09, p < 0.01; I2  = 94.90%). Subgroup analyses revealed possible variations in wound healing time based on wound types and regions. This study underscores the significant advantages associated with the use of moist dressings, including expedited wound healing, reduced infection rates, decreased frequency of dressing changes, and lower overall treatment costs.

Oxygen transmission rates of skin substitutes and graft survival

AIM

Oxygen is required for cell migration into the scaffold and for the survival of the overlying graft in the use of a single-layer scaffold. In the absence of diffusion from the avascular wound base, such as in areas above the bone/tendon, oxygen delivery from the lateral edges of the scaffold is important. This study compared the oxygen permeability of skin scaffolds, currently commercially available in Turkey (Nevelia®, MatriDerm®, and Pelnac®), in the lateral plane.

MATERIALS AND METHODS

To measure oxygen permeability, an interconnected closed system was created. Oxygen permeability was evaluated based on the color change that occurred as a result of the reaction of iron with oxygen. After the dermal matrices placed in the closed system were exposed to oxygen, the color change on the surface of the dermal matrices was measured, and electron microscopic images were recorded to compare deformation before and after the procedure.

RESULTS

Two scaffolds did not show deformation after the procedure while Pelnac® had minimal deformation. The oxygen rates on the nitrogen side of the test apparatus were found to be 29%, 34%, and 27% for Nevelia®, MatriDerm®, and Pelnac®, respectively; and the oxygen transmission lengths (length of color change) of these scaffolds in the lateral plane were 1, 2, and 0.5 cm, respectively.

CONCLUSION

Although none of the scaffolds showed significant deformation, and all continued to exhibit their scaffold properties after the procedure, MatriDerm® was determined to be the most suitable scaffold for use in avascular areas, with a 2-cm oxygen transmission length in terms of lateral oxygenation.

Delayed primary intention with full-thickness skin graft in distal interphalangeal injury: A rare case report

INTRODUCTION AND IMPORTANCE

The fingertip injury is the most common in the hand area. In this regard, skin grafting can be considered to preserve sensation, due to its functional importance, particularly for distal tip injuries. A full-thickness skin graft (FTSG) results in excellent function after engraftment and should be considered in reconstructing functionally and aesthetically important areas. Moreover, a thorough understanding of FTSG is required for a surgeon to have an excellent outcome.

CASE PRESENTATION

A 38-year-old man had the third fingertip injury of his right hand after being crushed by a mill. Physical examination revealed exposed bone distal to DIP, with intact periosteum and nail plate, negative active bleeding, and negative contaminants. There was no tendon or soft tissue left above the periosteum. In addition, an X-ray of the right manus revealed no fracture. The wound was applied with hydrogel and petroleum gauze to maintain hydration. A wound toilet was performed, followed by the closure of the wound with full-thickness skin grafting (FTSG). Follow-up was done in the first week and the fourth week after the procedure, as they showed good aesthetic results with satisfactory function. The sensory recovery showed normal result for touch and vibration. Meanwhile, sharp pain and warmth object sensation were minimally diminished.

CLINICAL DISCUSSION

A literature review concludes that FTSGs are generally unreliable in cases with over poorly vascularized beds, and FTSG will only work with no serious blood supply issues. Therefore, severe fingertip injury was reconstructed by the graft.

CONCLUSION

This procedure showed excellent graft survival with no additional surgical injury of the normal finger, satisfactory functional and aesthetic outcomes, and no need for secondary debulking procedures. Potential disadvantages consisted of insufficient volume of soft tissue and graft hyperpigmentation. However, delayed primary wound closure by FTSG may be an option for treating full-thickness finger defects with bone or tendon exposure.

Fabrication and Bioactivity of Peptide-Conjugated Biomaterial Tissue Engineering Constructs

Tissue engineering combines materials engineering, cells and biochemical factors to improve, restore or replace various types of biological tissues. A nearly limitless combination of these strategies can be combined, providing a means to augment the function of a number of biological tissues such as skin tissue, neural tissue, bones, and cartilage. Compounds such as small molecule therapeutics, proteins, and even living cells have been incorporated into tissue engineering constructs to influence biological processes at the site of implantation. Peptides have been conjugated to tissue engineering constructs to circumvent limitations associated with conjugation of proteins or incorporation of cells. This review highlights various contemporary examples in which peptide conjugation is used to overcome the disadvantages associated with the inclusion of other bioactive compounds. This review covers several peptides that are commonly used in the literature as well as those that do not appear as frequently to provide a broad scope of the utility of the peptide conjugation technique for designing constructs capable of influencing the repair and regeneration of various bodily tissues. Additionally, a brief description of the construct fabrication techniques encountered in the covered examples and their advantages in various tissue engineering applications is provided.

Self-Assembled Peptide Hydrogel for Accelerated Wound Healing: Impact of N-Terminal and C-Terminal Modifications

Wound dressings are required to provide a moist environment for wounds, protect against invading infections, expedite tissue regeneration, and improve wound healing efficiency. Developing biomaterials with all aforesaid properties is still a big challenge. However, peptide-based hydrogels have the potential to overcome these challenges as they are biocompatible, biodegradable as well as have the ability to mimic the extracellular matrix and provide an appropriate moist environment which is important for wound healing. With this in mind, we report the preparation and comparison of three hexapeptide-based hydrogels, LIVAGD, with the aim to understand the importance of the N-terminal protecting group as well as the C-terminal amino acid substitution on its various biological efficacies. Fmoc and acetyl groups were used for N-terminal peptide protection, while aspartic acid was substituted with lysine at the C-terminus. The resulting peptide-based hydrogels were compared. Fmoc peptide-based hydrogels exhibited efficient anti-inflammatory action along with improved biocompatibility while lysine provided enhanced antibacterial effect to the hydrogel. Additionally, in vivo efficacy was examined using a mouse model, and Fmoc hydrogels demonstrated an improved wound healing ability with ∼40 % faster healing rate in comparison to the reported acetylated peptide hydrogels.

Efficacy and Safety of Subfascial Epidural Drainage Protocol After Intraoperative Durotomy in Posterior Thoracic and Lumbar Spine Surgery: Reoperation Prevention and Outcomes Among Drained and Undrained Cohorts

BACKGROUND

Persistent cerebrospinal fluid (CSF) egress after durotomy in posterior thoracic or lumbar spine surgery may cause devastating complications. Persistent CSF leaks may require reoperation, which confers additional cost and morbidity.

OBJECTIVE

To evaluate the efficacy of our subfascial epidural drainage protocol in the setting of durotomy to prevent reoperation.

METHODS

A retrospective cohort study of drained and undrained cohorts was completed to identify factors associated with reoperation for persistent CSF leak-related symptoms. The efficacy and safety of this 7-day subfascial epidural drainage protocol was assessed by comparing reoperation incidence, perioperative complications, rehabilitation necessity, and readmissions.

RESULTS

In total, 156 patients underwent subfascial epidural drainage, and 14 were not drained. Subfascial drainage for up to 7 days was associated with a significantly lower incidence of reoperation than no drainage (3.3% vs 14%, respectively; P = .03). Perioperative complication incidence was similar between cohorts (12.8% vs 21.4%, respectively; P = .37), and length of stay was unchanged regardless of drainage (median 7 days). Subfascial drainage conferred a nearly 2-fold relative risk reduction in inpatient rehabilitation requirement (RR 0.55) and 3-fold relative risk reduction in 30-day (RR 0.31) and 90-day readmission (RR 0.36). Factors associated with reoperation among drained patients included drainage longer than 7 days, tobacco use, age younger than 50 years, and longer segment operations. Revision spine surgery was associated with reoperation among undrained patients.

CONCLUSION

When followed after durotomy, our subfascial epidural drainage protocol results in fewer reoperations than in an undrained cohort without prohibitive cost and no added morbidity.

Dressing or Not after Tubularized Incised Plate Urethroplasty

BACKGROUND

Many surgical techniques, as well as dressing models, were identified in the treatment of hypospadias. There are many publications in the literature that are the result of the effort to find the ideal dressing after hypospadias surgery. The dressing has some benefits; however, it has some adverse effects. The present study aimed to discuss outcomes of the patients who have been operated through the tubularized incised plate urethroplasty (TIPU) method and followed with and without dressing postoperatively.

METHODS

Patients operated on through the TIPU method between March 2015 and August 2019 were reviewed retrospectively. The patients were divided into two groups, dressing and undressing. Preoperative hypospadias severity was evaluated according to the Glans-Urethral Meatus-Shaft (GMS) scoring method. The care results of the patients were recorded. Postoperative outcomes were compared according to the Hypospadias Objective Scoring Evaluation (HOSE) scale, and statistical analyses were conducted. The results of both groups were compared statistically.

RESULTS

One hundred and nineteen patients were divided into two groups: dressing (n = 56) and nondressing (n = 63). The patients' average age was 3.54 ± 2.97 years in group 1 and 3.50 ± 3.01 years in group 2 (p = 0.940). There was not any statistically significant difference between the two groups for demographic data. Minimal bleeding had stopped in three patients in the nondressing group spontaneously before discharging. No severe edema or hematoma, which might have concerned the parents, appeared. Two (3.5%) and 3 (4.7%) patients underwent a maximum of three urethral dilation sessions in dressing and nondressing groups, respectively (p = 0.556). We found no significant difference between groups in the comparison of preoperative GMS and postoperative HOSE scoring.

DISCUSSION

The most important limitation of the study is that it is retrospective. Pre- and postoperative scoring systems are objective. The data obtained in the literature show that surgeons prefer to apply dressings commonly after the TIPU technique. Advantages and disadvantages of dressing are mentioned in the literature. Even if the paradigm is dressing in hypospadias surgery, according to the results of our study, dressing may not affect the functional and cosmetic results of TIPU repair.

CONCLUSION

Postoperative functional and cosmetic results of TIPU in hypospadias appear to be independent of dressing. However, the results must be supported by further research.

Skin and subcutaneous fascia closure at caesarean section to reduce wound complications: the closure randomised trial

BACKGROUND

Wound infection is a common complication following caesarean section. Factors influencing the risk of infection may include the suture material for skin closure, and closure of the subcutaneous fascia. We assessed the effect of skin closure with absorbable versus non-absorbable suture, and closure versus non-closure of the subcutaneous fascia on risk of wound infection following Caesarean section.

METHODS

Women undergoing caesarean birth at an Adelaide maternity hospital were eligible for recruitment to a randomised trial using a 2 × 2 factorial design. Women were randomised to either closure or non-closure of the subcutaneous fascia and to subcuticular skin closure with an absorbable or non-absorbable suture. Participants were randomised to each of the two interventions into one of 4 possible groups: Group 1 - non-absorbable skin suture and non-closure of the subcutaneous fascia; Group 2 - absorbable skin suture and non-closure of the subcutaneous fascia; Group 3 - non-absorbable skin suture and closure of the subcutaneous fascia; and Group 4 - absorbable skin suture and closure of the subcutaneous fascia. The primary outcomes were reported wound infection and wound haematoma or seroma within the first 30 days after birth.

RESULTS

A total of 851 women were recruited and randomised, with 849 women included in the analyses (Group 1: 216 women; Group 2: 212 women; Group 3: 212 women; Group 4: 211 women). In women who underwent fascia closure, there was a statistically significant increase in risk of wound infection within 30 days post-operatively for those who had skin closure with an absorbable suture (Group 4), compared with women who had skin closure with a non-absorbable suture (Group 3) (adjusted RR 2.17; 95% CI 1.05, 4.45; p = 0.035). There was no significant difference in risk of wound infection for absorbable vs non-absorbable sutures in women who did not undergo fascia closure.

CONCLUSION

The combination of subcutaneous fascia closure and skin closure with an absorbable suture may be associated with an increased risk of reported wound infection after caesarean section.

TRIAL REGISTRATION

Prospectively registered with the Australian and New Zealand Clinical Trials Registry, number ACTRN12608000143325 , on the 20th March, 2008.

Tissue Augmentation in Wound Healing: the Role of Endothelial and Epithelial Cells

Introduction

Wounds and their complications present a frequent cause of morbidity and mortality in everyday clinical practice. In order to reduce the wound burden, much effort has been directed into the physiology of healing and new therapeutic approaches.

Aim

This paper provides an overview from the literature about the role of endothelial and epithelial cells in tissue filler employment for wound healing.

Material and Methods

The scientific literature was reviewed through PubMed, Medline and Science Direct. The articles were chosen in correlation with the study objective and their scientific relevance.

Results

Successful wound healing depends on many diverse processes, cell types and molecular mediators. The definitive aim of wound healing is a properly healed wound. Tissue fillers are becoming an important alternative in wound management, although augmentation of soft tissue can present a demanding problem due to the difficulties in tissue survival. In order to prevent its failure, an optimal vascular network needs to form from wound edges into the filler.

Conclusions

Because of the importance of chemotaxis and angiogenesis in various physiological and pathological processes, both events present an extensive area of intense research. Additionally, epithelial cells are needed to cover the wound defect and sealing the wound environment from outer world.

Dual-functional core-shell electrospun mats with precisely controlled release of anti-inflammatory and anti-bacterial agents

Acute wounds are worldwide problems affecting millions of people and causing heavy economic burden to national healthcare systems. Herein, we describe novel wound dressing materials relying on core/shell electrospun mats incorporated with flurbiprofen and vancomycin for achieving programmable release of anti-inflammatory and anti-bacterial agents. The shell matrix of nanofibers consisted of polyethylene oxide while the core matrix was made from a blend of silk and collagen. Several optimal mat architectures were engineered with distinct configurations, of which release profiles displayed an exponential trend, which indicates a first-order process following Fickian diffusion behavior. The flurbiprofen release lasted from 2 to 6 days, which was much faster compared to the one of vancomycin prolonged up to about 20 days. Mechanical data indicated tensile modulus, tensile strength, elongation before break of core/shell electrospun mats became enhanced or comparable to those for human skin after methanol vapor treatment. Desirable release kinetics and mechanical characteristics achieved by novel core/shell electrospun mats were attributable to induced enrichment of β-sheet phase in silk via methanol vapor treatment as well as water annealing process with time and judicious selections for matrix materials and mat configurations. The design principles considered in this study successfully addressed a range of inflammation and infection requirements in wound healing, potentially guiding construction of other biomedical coatings and devices.

Synthetic polymeric biomaterials for wound healing: a review

Wounds are of a variety of types and each category has its own distinctive healing requirements. This realization has spurred the development of a myriad of wound dressings, each with specific characteristics. It is unrealistic to expect a singular dressing to embrace all characteristics that would fulfill generic needs for wound healing. However, each dressing may approach the ideal requirements by deviating from the 'one size fits all approach', if it conforms strictly to the specifications of the wound and the patient. Indeed, a functional wound dressing should achieve healing of the wound with minimal time and cost expenditures. This article offers an insight into several different types of polymeric materials clinically used in wound dressings and the events taking place at cellular level, which aid the process of healing, while the biomaterial dressing interacts with the body tissue. Hence, the significance of using synthetic polymer films, foam dressings, hydrocolloids, alginate dressings, and hydrogels has been reviewed, and the properties of these materials that conform to wound-healing requirements have been explored. A special section on bioactive dressings and bioengineered skin substitutes that play an active part in healing process has been re-examined in this work.

Application of Materials as Medical Devices with Localized Drug Delivery Capabilities for Enhanced Wound Repair

The plentiful assortment of natural and synthetic materials can be leveraged to accommodate diverse wound types, as well as different stages of the healing process. An ideal material is envisioned to promote tissue repair with minimal inconvenience for patients. Traditional materials employed in the clinical setting often invoke secondary complications, such as infection, pain, foreign body reaction, and chronic inflammation. This review surveys the repertoire of surgical sutures, wound dressings, surgical glues, orthopedic fixation devices and bone fillers with drug eluting capabilities. It highlights the various techniques developed to effectively incorporate drugs into the selected material or blend of materials for both soft and hard tissue repair. The mechanical and chemical attributes of the resultant materials are also discussed, along with their biological outcomes in vitro and/or in vivo. Perspectives and challenges regarding future research endeavors are also delineated for next-generation wound repair materials.

Surgical suture releasing macrophage-targeted drug-loaded nanoparticles for an enhanced anti-inflammatory effect

An anti-inflammatory nanoparticle-coated suture reduces inflammation and pain at the wound site.

Innovative approaches in wound healing: trajectory and advances

Wound is one of the oldest suffering associated with the mankind and its history is as old as humanity. Advances in the field of medical sciences created a pile of knowledge and paved the path for the development of a separate branch specifically devoted for wound healing. The understanding and treatment strategies for wound healing have gone through a great revolution. This article reviews all the aspects of wound healing including the pathway, types and recent advances made in the wound care management in particular moist wound dressings using natural polymers, skin grafts, debridement, growth factor and drug delivery.

TGF-β1 expression in wound healing is acutely affected by experimental malnutrition and early enteral feeding

Malnutrition is associated with the delay or failure of healing. We assessed the effect of experimental malnutrition and early enteral feeding with standard diet or diet supplemented with arginine and antioxidants on the levels of mRNA encoding growth factors in acute, open wound healing. Standardised cutaneous dorsal wounds and gastrostomies for enteral feeding were created in malnourished (M, n = 27) and eutrophic control (E, n = 30) Lewis male adult rats. Both M and E rats received isocaloric and isonitrogenous regimens with oral chow and saline (C), standard (S) or supplemented (A) enteral diets. On post-trauma day 7, mRNA levels of growth factor genes were analysed in wound granulation tissue by reverse transcription polymerase chain reaction (RT-PCR). M(C) rats had significantly lower transforming growth factor β(TGF-β1 ) mRNA levels than E(C) rats (2·58 ± 0·83 versus 3·53 ± 0·57, P < 0·01) and in comparison with M(S) and M(A) rats (4·66 ± 2·49 and 4·61 ± 2·11, respectively; P < 0·05). VEGF and KGF-7 mRNA levels were lower in M(A) rats than in E(A) rats (0·74 ± 0·16 versus 1·25 ± 0·66; and 1·07 ± 0·45 versus 1·79 ± 0·89, respectively; P≤ 0·04), but did not differ from levels in E(C) and M(C) animals. In experimental open acute wound healing, previous malnutrition decreased local mRNA levels of TGF-β1 genes, which was minimised by early enteral feeding with standard or supplemented diets.

Is tissue augmentation a reality in biosurgery? An experimental study of endothelial cell invasion into tissue filler

New therapeutic approaches for wound treatment are evolving. Non healing wounds in oncology and after trauma may be cured by a novel technique of tissue augmentation with soft tissue fillers. The principle resides in filling the wound with collagen filler in order to seal the defect and promote healing. Successful angiogenesis forms the basis of tissue filler survival and determines the outcome of the healing process. During this study, basic data about endothelial cell invasion into collagen-made substratum was collected that could be used for neoangiogenesis studies in tissue augmentation techniques for large wound defect treatment. In the in vitro assay, the human umbilical vein endothelial cells (HUVEC) grow into a three-dimensional framework of collagenous tissue fillers, forming the basic step for angiogenesis. After heparins were used as chemotactic agents, a typical bell-shaped relationship between chemotaxis and agent concentrations was found. Significant cell infiltration was present in the assays with chemotactic agents. These observations support the potential for tissue augmentation with soft tissue fillers that could be used in acute and chronic non healing traumatic and oncology wounds after extensive surgical resections and radiotherapy.

The role of whirlpool in wound care

Evidenced-based-wound management continues to be a cornerstone for advancing patient care. The purpose of this article is to review the use of whirlpool as a wound treatment in light of evidence, outcomes, and potential harm. Whirlpool was initially harnessed as a means to impart biophysical energy to a wound or burn to enhance mechanical debridement and cleansing. Other credible single-patient-use technologies which provide an alternative to whirlpool in wound care are presented.

Effectiveness of hydrocolloid dressing in postoperative hip and knee surgery: literature review and our experience

Hydrocolloid dressings are impermeable dressings that provide an optimal environment for wound healing. These dressings are very effective in healing chronic wounds but evidence regarding their use for the post-operative knee and hip surgery is scarce. Our experience shows that hydrocolloid dressing (Duoderm) helps in preventing not only superficial surgical site infection (SSSI) but also blister formation in patients undergoing lower limb orthopaedic surgery.

Postoperative wound care regimen in open septorhinoplasty

The many benefits of the open-approach septorhinoplasty should not be excluded on the basis of columellar scarring alone. Technical factors that contributed to the favorable outcome of the columellar scar included proper planning of location and design of the incision used, meticulous closure, and good postoperative care. In the current study, we describe a simple postoperative wound care procedure that allows clean visualized wound with less crust formation, easy removal of the sutures by the surgeon, and better columellar scar in the early postoperative period.

Characterization and quantification of wound-induced hair follicle neogenesis using in vivo confocal scanning laser microscopy

BACKGROUND

In vivo confocal scanning laser microscopy (CSLM) is a recently developed non-invasive technique for visualizing microscopic structures with the skin. CSLM has been used to characterize proliferative and inflammatory skin diseases, neoplastic skin lesions and pigmented lesions.

OBJECTIVE

Here, we assessed the ability of CSLM to evaluate the formation of neogenic hair follicles after a full-thickness wound in mice.

METHODS

Full-thickness wounds were made on the dorsal skin of 3-week-old mice. After scab detachment (SD), the number, width, length, space and volume of neogenic hair follicles were analyzed using CSLM. The results were compared with those from conventional methods, including staining for alkaline phosphatase (AP) and keratin 17 (K17) as well as histology.

RESULTS

Quantification of neogenic hair follicles using CSLM compared favorably with the results from direct measurements on isolated epidermal tissue after immunostaining for K17, a marker for the epithelial portion of new hair follicles. CSLM detected 89% of K17-stained follicles. CSLM more accurately quantified the number of new follicles compared with AP staining, which detects the dermal portion of the new follicle. The width and length measurement from CSLM and histology were very close and correlated with each other. The minimum length of a neogenic hair follicle that could be detected by CSLM was 21 μm. The space between neogenic hair follicles was decreased in histological sections compared with CSLM.

CONCLUSION

CSLM is an accurate and valuable method for counting and measuring neogenic hair follicles non-invasively. CSLM produces images similar to histology in mice. Measurements of microstructures using CSLM more accurately reflect actual sizes as this technique avoids fixation artifacts. In vivo visualization of developing follicles with CSLM allows the detection of serial changes in hair follicle formation, thus conserving the numbers of mice required for studies and improving the detection of temporal changes in developing hair follicles.

Short-term specialized enteral diet fails to attenuate malnutrition impairment of experimental open wound acute healing

OBJECTIVE

We assessed the effect of enteral refeeding on the morphology, gene expression, and contraction of acute open wounds in previously malnourished rats using two different enteral diets.

METHODS

Adult male isogenic Lewis rats divided into two groups (eutrophic, n = 30; and previously malnourished, 12-15% body weight loss, n = 27) were subjected to cutaneous dorsal wounds and gastrostomy. Control rats received a standard oral diet (AIN-93M chow) plus enteral saline solution. Subject rats received chow plus a standard enteral diet or an enteral diet enriched with arginine and antioxidants. On post-trauma days 7 and 14, wound granulation tissue samples were collected for morphologic analysis using hematoxylin and eosin and picrosirius stain or immunohistochemistry slides and real-time polymerase chain reaction for collagen I and III gene expression. Wound contraction was also evaluated by comparing wound images from days 0, 7, and 14.

RESULTS

Malnourished control rats had increased intensity and duration of wound inflammation, impaired increase of fibroblast cells contingent on post-trauma days 7 to 14, decreased expression of collagen III, and less wound contraction compared with eutrophic control rats. A specialized enteral diet did not improve wound healing of malnourished rats but did promote wound contraction at post-trauma day 7 in eutrophic rats.

CONCLUSION

Short-term enteral refeeding, even with a specialized diet, failed to protect previously wounded malnourished rats from a prolonged inflammatory phase and impaired healing.

The wound healing process: an overview of the cellular and molecular mechanisms

Wound healing remains a challenging clinical problem and correct, efficient wound management is essential. Much effort has been focused on wound care with an emphasis on new therapeutic approaches and the development of technologies for acute and chronic wound management. Wound healing involves multiple cell populations, the extracellular matrix and the action of soluble mediators such as growth factors and cytokines. Although the process of healing is continuous, it may be arbitrarily divided into four phases: (i) coagulation and haemostasis; (ii) inflammation; (iii) proliferation; and (iv) wound remodelling with scar tissue formation. The correct approach to wound management may effectively influence the clinical outcome. This review discusses wound classification, the physiology of the wound healing process and the methods used in wound management.

Activation of human platelet-rich plasmas: effect on growth factors release, cell division and in vivo bone formation

OBJECTIVES

Aims of this controlled study were to determine the effects of activated human platelet-rich plasmas (PRPs) on early and mature bone formation in vivo, and to characterize the effect of PRP activation on growth factors release and endothelial cell division in vitro.

MATERIAL AND METHODS

PRPs were prepared from four volunteers with the platelet concentrate collector system (PCCS) system and activated with three concentrations of calcium and thrombin. Platelet-derived growth factor (PDGF)-BB, vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-beta) and interleukin-1beta (IL-1beta) levels released in supernatants were measured by ELISA, at time 0, 1h, 24h and 6 days following PRP activation. Mitogenic potential of PRP supernatants were tested on endothelial cells in vitro, and the effects of activated human PRPs on bone formation in vivo were measured in athymic rats by micro-CT analyses.

RESULTS

Activation of PRPs with calcium and thrombin triggered an immediate release of VEGF, PDGF-BB and TGF-beta and a delayed release of IL-1beta in PRP supernatants. Higher endothelial cell division was observed with supernatants from activated PRPs than from non-activated PRPs. Positive correlations were observed between VEGF levels and endothelial cell division and bone formation. A negative correlation was also found between PDGF-BB concentration and bone formation. However, early and mature bone formations with activated PRPs did not significantly differ from the ones obtained in the control group.

CONCLUSIONS

Activation of PRPs with calcium and thrombin regulates growth factors release and endothelial cell division in vitro. However, activated PRPs does not improve the early or mature bone formations in vivo in this athymic rat model.

Hyperbaric oxygen therapy for malignancy: a review

One unique feature of tumors is the presence of hypoxic regions, which occur predominantly at the tumor center. Hypoxia has a major impact on various aspects of tumor cell function and proliferation. Hypoxic tumor cells are relatively insensitive to conventional therapy owing to cellular adaptations effected by the hypoxic microenvironment. Recent efforts have aimed to alter the hypoxic state and to reverse these adaptations to improve treatment outcome. One way to increase tumor oxygen tensions is by hyperbaric oxygen (HBO) therapy. HBO therapy can influence the tumor microenvironment at several levels. It can alter tumor hypoxia, a potent stimulus that drives angiogenesis. Hyperoxia as a result of HBO also produces reactive oxygen species, which can damage tumors by inducing excessive oxidative stress. This review outlines the importance of oxygen to tumors and the mechanisms by which tumors survive under hypoxic conditions. It also presents data from both experimental and clinical studies for the effect of HBO on malignancy.

The effect of hyperbaric oxygen therapy on tumour growth in a mouse model of colorectal cancer liver metastases

BACKGROUND AND AIMS

Hyperbaric oxygen (HBO) therapy involves the administration of 100% oxygen at high pressure. It has been used to treat a variety of conditions including non-healing wounds, carbon monoxide poisoning, and as an adjuvant to radiotherapy or chemotherapy. The effect of HBO alone on the growth of malignancy remains controversial. This study investigates the impact of HBO on tumour growth, kinetics and microcirculation of colorectal cancer liver metastases in an experimental model.

METHODS

Male CBA mice were induced with colorectal liver metastases via an intrasplenic injection of a murine derived colorectal cell line. Tumours were examined using quantitative stereological analysis, histology and scanning electron microscopy of microvascular resin casts. The effect of HBO on tumour proliferation and apoptosis was quantified using immunohistochemistry.

RESULTS

Daily exposure to HBO at 2.4 atm for 90 min had no effect on the volume of liver metastases. At day 13, HBO caused a significant reduction in tumour necrosis and proliferation compared to the non-HBO group (p=0.002 and p=0.008, respectively). By day 25 however, no differences were observed (p>0.05). No differences in apoptosis or microvascular architecture were observed.

CONCLUSION

HBO did not have a tumour stimulatory effect on colorectal liver metastases and may potentially be used safely in conjunction with other therapeutic treatment modalities.

Nutrition and wound healing: the necessity of assessment

Wound healing is an intricate affair and good nutritional status is essential to promote effective growth and repair of body tissue. Nutrients play vital roles in the constitution of a well-balanced diet and any depletion in a person's nutritional intake, especially proteins, can lead to malnutrition and protein-energy malnutrition, conditions which are known to have considerable impact on health and well-being and on the wound healing process. A holistic nutritional assessment is paramount to the early detection of nutritional deficiency and the use of recognized nutritional assessment tools can significantly increase practitioners' awareness in its undertaking. While nurses are renowned to have a central role in the management of the patient who, nutritionally are at risk, it is equally important to remember that overall management is essentially a multidisciplinary task.

Fascial Dehiscence after Trauma Laparotomy: A Sign of Intra-Abdominal Sepsis

Fascial dehiscence (FD) after trauma laparotomy is associated with technical failure, wound sepsis, or intra-abdominal infection (JAI). The association of IAI with FD is inadequately evaluated. Knowing about its presence is essential to guide clinical diagnosis and management. Our objective was to identify the incidence and risk factors of IAI in patients with FD. We performed a medical record review of 55 trauma patients with FD. Patients with IAI were compared to patients without IAI and FD patients to all trauma laparotomy patients during the same period. Statistical significance was at P < 0.05. Thirty-nine (71%) FD patients had IAI, significantly higher than all trauma laparotomies (4.6%, P < 0.0001). Only 31 per cent of patients underwent laparotomy and drainage while 69 per cent received CT-guided percutaneous drainage followed by expectant management. Similarly, 33 per cent of the non-IAI group had operative management. No differences were found between the two groups in any of the examined factors. The majority of trauma patients with FD have IAI. No clinical or laboratory factors help identify FD patients likely to have IAI. Therefore, FD should be viewed as a sign of possible underlying IAI. Appropriate radiographic imaging or direct visualization of the entire abdominal cavity should be pursued before managing the dehisced fascia.

Cosmetic concerns in posterior fossa skull base surgery

Although cosmetic defects produced by posterior fossa surgery may not seem obvious, a poor cosmetic result can overshadow an otherwise successful operation. It is important to approach the operation with knowledge that each phase of a surgical procedure either directly or indirectly influences the eventual cosmetic result. The careful use of anatomic dissection and repair and attempts to reconstitute bony defects to their native contour as well as avoidance of complications all contribute to excellent cosmetic outcomes.

Evidence-based surgical wound care on surgical wound infection

Surgical wound infection is an important outcome indicator in the postoperative period. A 3-year prospective cohort epidemiological study of 2202 surgical patients from seven surgical wards across two hospitals was carried out using gold standard surveillance methodology. This involved following patients up as inpatients and postdischarge surveillance to 30 days by an independent observer. The results led to the development of a mathematical model for risk of clean, elective surgical wound infection. Risk of surgical wound infection was increased by smoking, higher body mass index, presence of malignancy, haematoma formation, increasing numbers of people in theatre, adherent dressing usage, and higher times to suture removal (P<0.05). The results show that this type of surveillance is an effective way of collecting accurate data on wound infection rates. It was noted that patient care practices affected the surgical wound infection rate and the surveillance was used to facilitate the adoption of evidence-based practice, through recommendations for clean surgery, to reduce the risk from extrinsic risk factors for wound infection. As a result of the implementation of this evidence-based practice there was a significant reduction (P<0.05) in the clean wound infection rate.

Food and wounds: nutritional factors in wound formation and healing

Nutrition is a crucial aspect of a holistic approach to the healing of wounds, including pressure ulcers and leg ulcers. Poor nutritional status and support can delay the wound healing process or cause inadequate healing when nutritional deficiencies are not corrected. Nutritional screening is an important part of the overall clinical assessment of patients. Nurses based in hospital and the community have a key role to play in identifying and monitoring patients who may be nutritionally at risk and require nutritional support to aid the wound healing process. Patients' nutritional requirements may need to be met through the use of nutritionally complete supplements or, if oral intake is poor, with enteral or parenteral nutrition.