The use of fat grafting and platelet-rich plasma for wound healing: A review of the current evidence

Use of autologous platelet-rich plasma for skin graft preservation: an experimental comparative study

OBJECTIVE

In this experimental study, we aimed to determine whether platelet-rich plasma (PRP) is a suitable preservative for dermo-epidermal grafts. An additional objective was to investigate how long grafts can be stored without biological degradation.

METHODS

We compared pig skin graft preservation using PRP versus saline solution and crystalloid Custodiol®, which is used for hypothermic preservation of organs for transplantation. Grafts (10 × 10 mm) were placed on gauze impregnated with one of the tested solutions, and stored for 3, 7, 11, and 15 days at a constant temperature of 4°C. We evaluated a total of 240 pig skin samples: 120 by histopathology and 120 by fluorescence optical microscopy.

RESULTS

Overall, Custodiol® solution appeared to be the best medium for preservation of dermo-epidermal grafts, with beneficial properties manifested on days 7 and 11. Although we expected PRP to be a better preservative than saline, this was not confirmed by our results, as we found no significant difference between these two media. In fact, by day 3, the histopathological results were better with standard saline solution than with PRP. On day 15, with each tested solution, some samples showed histological changes that are incompatible with graft viability.

CONCLUSION

Overall, Custodiol® appears to be the best medium for dermo-epidermal graft preservation. Moreover, the present findings suggest a maximum graft storage time of 11 days in all of the tested solutions. We do not recommend using grafts stored for 15 days, due to isolated signs of graft biodegradation with all solutions.

The Impact of Platelet-Rich Plasma Application during Cesarean Section on Wound Healing and Postoperative Pain: A Single-Blind Placebo-Controlled Intervention Study

Background/Objectives: The aim of this study was to evaluate if platelet-rich plasma (PRP) application into the wound during cesarean delivery improves wound healing and reduces pain in the postoperative period. Materials and Methods: A total of 46 patients undergoing cesarean section (CS) were included in this single-blind placebo-controlled intervention study: 23 women in the PRP group and 23 in the placebo group. Every patient was asked to evaluate pain by using the Visual Analogue Scale (VAS) immediately after surgery, as well as 6 and 12 h after the surgery. The use of analgetics was also recorded. The postoperative scar was assessed using the Patient and Observer Scar Assessment Scale (POSAS). Results: There was no case of wound dehiscence in either group. Significant differences between the groups in the scar quality assessment were detected in both patient and doctor POSAS results on days 8, 30 and 90 after surgery in the favor of the PRP group. There was no difference in the pain intensity assessment on the VAS recorded after surgery, but PRP patients required fewer paracetamol doses per day than the control group. Conclusions: PRP application during CS significantly improved wound healing in both short- and long-term assessment. Although it did not influence postoperative pain intensity, it may reduce the use of analgetics after surgery.

Artificial dermis combined with negative pressure wound therapy and platelet-rich plasma to treat traumatic wounds: a retrospective study

OBJECTIVE

The reconstruction of complex soft tissue defects with exposure of bones and tendons represents an increasing challenge in wound care, especially in large extremity wounds. The aim of this study was to detect the clinical efficacy of combined use of negative pressure wound therapy (NPWT), artificial dermis (ADM), platelet-rich plasma (PRP) and split-thickness skin grafting (STSG) in the reconstruction of large traumatic extremity skin defects.

METHOD

In this study, eight cases were treated with combined therapies for repairing complex extremity wounds and the results were reviewed retrospectively. After surgical debridement, all wounds received ADM, PRP and delayed STSG, which were all aided with NPWT.

RESULTS

The patients consisted of five males and three females, with a mean age of 44 years. A total of six lower extremity wounds were located at the foot/ankle, with exposed tendon in five, bone exposure in three and both in two. Of the group, two patients had exposed tendon on arm/hand wounds. The size of wounds and ADM averaged 126cm2 and 42.3cm2, respectively. ADM was used to cover the exposed bone or tendon, the granulation and muscular tissue were covered with vacuum sealing drainage (VSD) directly, for NPWT. The survival rate of ADM averaged 98.9%. The average time for survival of ADM was 12.8 days and the mean uptake of autologous skin graft was 93.5%. Only one patient received repeated skin grafts. All patients achieved successful healing and reported no complications. The mean length of hospital stay was 36.1 days.

CONCLUSION

Our study revealed that ADM in conjunction with NPWT, PRP and STSG could be used for repairing large traumatic extremity wounds. Wound closure was achieved without flaps, the aesthetic and functional outcomes were acceptable, and only one patient developed a 35% loss of skin graft.

DECLARATION OF INTEREST

This work was supported by grants from the Natural Science Foundation of Hubei Province (grant no. 2020CFB464) and Youth Foundation of Wuhan Municipal Health Commission (grant no. WX20Q15). The authors have no conflicts of interest to declare.

A bibliometric analysis of trends in the application of platelet-rich plasma in cosmetics research between 2001 and 2022

BACKGROUND

Several studies have been conducted on using platelet-rich plasma (PRP) to treat cosmetic issues. Nonetheless, no bibliometric analyses of publications in this field exist. Bibliometrics is an effective tool for methodically assessing the current state of research on a particular topic. This study examines the literature published in this field since 2000 and depicts the resulting network.

METHODS

The Web of Science Core Collection was searched for any publications mentioning the use of PRP in cosmetic or aesthetic therapy published between 2001 and 2022. The author, region, institution, journal, cited journal, and keywords were extracted, and the bibliometric analysis was carried out using CiteSpace and R studio.

RESULTS

There were a total of 306 items retrieved. The first publication in this field appeared in 2001, and the number of articles published increased over the next 21 years. Saedi Nazanin is the author with the most publications. The most prolific nations and institutions were the United States and the Fourth Military Medical University, respectively. Similarly, most articles and citations were found in the Journal of Cosmetic Dermatology and Plastic and Reconstructive Surgery. After performing a cluster analysis on the keywords of published publications, we discovered that most of the published literature focused on using PRP in rejuvenation, mechanism, and combination with MSCs. These topics are still at the frontier of future research.

CONCLUSION

Since the first study in this field was published in 2001, PRP used in cosmetic clinics has been studied. Although early effects have been observed, numerous challenges remain, including a lack of higher-quality clinical studies and explanations of PRP's mechanism. The bibliometric analysis conducted for the purpose of this article provides a summary of academic hotspots and research frontiers, as well as insights and pointers for future productive research.

Hyperbaric Oxygen Therapy for Diabetic Foot Ulcers Based on Wagner Grading: A Systematic Review and Meta-analysis

Background

Diabetic foot ulcers (DFUs) are common complications of uncontrolled diabetes mellitus that can result in infection and amputation of the lower extremities. This study compared the benefits and risks of hyperbaric oxygen therapy with those of other DFU treatments, based on the Wagner grading system.

Methods

Systematic searches for randomly controlled trials using hyperbaric oxygen therapy for DFUs were performed using PubMed, the Cochrane Library, and Embase. Data regarding demographics, wound healing, minor and major amputations, operative debridement, nonhealing wounds, and adverse effects were analyzed based on Wagner grades, using RevMan 5.4.1 and Microsoft Excel.

Results

Hyperbaric oxygen therapy was significantly superior to other treatments for wound healing rates 8 or more weeks after the final treatment (RR = 2.39; 1.87-3.05; P < 0.00001) minor/distal amputations (RR = 0.58; 0.43-0.80; P < 0.007), and major/proximal amputations (RR = 0.31; 0.18-0.52; P < 0.00001) for the 14 studies analyzed. In addition, this therapy increased the rate of complete wound healing for Wagner grades II (RR = 21.11; 3.05-146.03; P = 0.002), III (RR = 19.58; 2.82-135.94, P = 0.003), and IV (RR = 17.53; 2.45-125.44; P = 0.004); decreased the minor/distal amputation rate for grade III (RR = 0.06; 0.01-0.29; P = 0.0004) and the major/proximal amputation rate on for grade IV (RR = 0.08; 0.03-0.25; P < 0.0001); and decreased the operative debridement rate for Wagner grade II (RR = 0.09; 0.01-0.60; P = 0.01).

Conclusions

Moderate-quality evidence revealed that adjunctive hyperbaric oxygen therapy improved DFU wound healing for Wagner grades II, III, and IV; prevented minor and major amputations for grades III and IV, respectively; and prevented operative debridement in grade II wounds.

Effect of MicroRNA-146a Modified Adipose-Derived Stem Cell Exosomes on Rat Back Wound Healing

Objective: To investigate the effect of MicroRNA-146a modified adipose-derived stem cell exosomes on the proliferation and migration of fibroblasts and the therapeutic effect on wound healing. Methods: Culture and identification of human adipose-derived stem cells (hASCs), miRNA-146a minic vector was constructed and transfected into hASCs, the exosomes of the empty group and overexpression group were extracted, identified, and quantitatively analyzed after 24 h of successful transfection. The exosomes were added into National Institute of Health Mouse Embryonic Fibroblasts (NIH/3T3) and cultured for 48 h, the proliferation and migration ability of NIH/3T3 fibroblasts was detected. The expression of serpin family H member 1 (SERPINH1) and phosphorylated extracellular regulated protein kinase (p-ERK) was detected by Western blot. The model of back wound was established. The exosomes were injected into 4 different sites with the shape of "cross" around the wound, and the scar diameter of the skin defect was measured at 3, 7, and 11 days, the skin of the defect was taken on the 14th day. platelet endothelial cell adhesion molecule-1 (CD31) was detected by immunofluorescence staining to evaluate angiogenesis, and Western blot was used to detect the expression of SERPINH1 and p-ERK. Results: The miR-146a mimic-exosome promoted the proliferation and migration of fibroblasts, and the expression of SERPINH1 and p-ERK2 was up-regulated. After the rats were treated with exosomes, the wound area decreased rapidly, neovascularization was promoted, and the expression of SERPINH1 and p-ERK2 was up-regulated. Conclusions: MicroRNA-146a modified adipose stem cell exosomes could regulate the expression of SERPINH1 and p-ERK, promote the migration and proliferation of fibroblasts, and neovascularization to promote the wound healing of rat back.

Regenerative Therapies for Basal Thumb Arthritis-A Systematic Review

Basal thumb arthritis is a painful and debilitating pathology that can severely reduce a patients' quality of life. Common therapies include oral pain control, local steroid injections and/or surgery. Yet, therapeutic data on long-term improvement and even cartilage repair are scarce. This review aims to present the currently available literature on novel therapies for basal thumb arthritis, including platelet-rich plasma (PRP), fat grafting and phototherapy, and investigate their potential efficacy. The entire OVID database and PubMed were searched for studies containing the topics PRP injection, lipofilling, laser treatment and regenerative treatment for carpometacarpal arthritis. Seven studies on the effect of fat tissue on basal thumb arthritis were found. Four authors reported on PRP injections, one RCT examined a combinational treatment of PRP and fat grafting, another phototherapy for the thumb joint and one prospective trial on chondrocyte transplantation was found. Pain improvement and decreased impairment were reported in the majority of PRP and/or fat grafting studies as well as after chondrocyte implantation. Phototherapy did not significantly improve the condition. This review revealed that only limited data on regenerative therapies for carpometacarpal arthritis are currently available, yet PRP and lipofilling show promising results and merit further investigation.

Long-term Results After Autologous Fat Transfer for Treatment of Chronic Lower Extremity Wounds

Autologous fat transfer may offer a simple and effective treatment option for chronic wound patients, delivering adipose-derived stem cells, with potent regenerative attributes. Nevertheless, the clinical benefit has not yet been sufficiently demonstrated. A total of 39 wound patients were treated with autologous fat transfer (AFT) and matched with a control group, according to the identified confounding variables "gender" and "method of defect closure." All data were acquired retrospectively. Primary outcome was "wound closure" and "reduction of wound size."After a follow-up of 48 weeks, there was no significant difference in primary outcome (wound closure P = .54) between both groups. The relative wound reduction after fat transfer was 69.9% ± 42.7% compared to 53.4% ± 106.8% in the control group (P = .91). Subgroup analysis of all patients, healed by secondary intention, revealed an increased wound size reduction (P = .03) and wound closure rate (P = .20) in the case group after 12 weeks. No adverse events were recorded. Fat grafting can reduce the wound size if left to secondary healing and may be considered individually for reconstructive purposes. A repeated application of autologous fat might be beneficial due to a temporary effect.

Comparison between platelet-rich plasma (PRP) and mechanically emulsified fat grafts in management of chronic wounds

BACKGROUND

chronic wounds represent a challenge in treatment, due to diverse pathogenesis, resistance to ordinary treatment complex and lack of direct methods of treatment In this study, the aim is to compare the effect of Platelet -rich plasma (PRP) and mechanically emulsified fat grafts on the outcome of the healing process of chronic wounds.

PATIENTS AND METHODS

In the current study, 30 patients with chronic wounds were divided into two groups (Group I, 15 patients had application of PRP on chronic wounds). Whereas (Group II, 15 patients had application of mechanically emulsified fat on chronic wounds). In both groups assessment of the healing rates and histopathological changes that were determined by observing the parameters of wound healing, including peri-lesional skin quality, observation of the wound size and depth, assessment of the pain indicated by Visual analog scale score.

RESULTS

Patient were followed up for 6 months. Group II showed a better healing rate 64% in comparison to Group I 55%. Wound parameters and pain score were recorded in both groups with no statistically significant difference.

CONCLUSION

Both PRP and mechanically emulsified fat grafts were found to be efficient treatment modalities in management of chronic "non-healing" wounds. But mechanically emulsified fat grafts represent a better treatment method for chronic wounds.

Platelet-Rich Plasma Combined Fat Transplantation for the Treatment of Bleomycin-Induced Murine Scleroderma

BACKGROUND

Low-fat retention induced by inflammation limits the clinical application of fat grafting for treating localized scleroderma (LS) patients. Novel methods to improve the therapeutic outcome are needed.

OBJECTIVE

The aim of the study is to investigate the effect of platelet-rich plasma (PRP)-assisted fat transplantation on skin fibrosis and adipose survival in the LS model.

METHODS

The LS model was established by the injection of bleomycin into BALB/C nude mice, which were randomly divided into the following 4 groups: healthy control, LS disease group model, fat transplantation group, and PRP+ fat transplantation group. The mice received a subcutaneous injection at back with phosphate-buffered saline, fat, or 20% PRP+ fat. Factors of immunoregulation, angiogenesis and adipogenesis were measured.

RESULTS

Platelet-rich plasma-combined fat transplantation significantly attenuated dermis fibrosis by reducing the production of type III collagen. The fat retention in the PRP+ fat transplantation group was 43 ± 4 mg, significantly higher than 22 ± 15 mg in the fat transplantation group (P = 0.0416). The level of tumor necrosis factor α and interleukin 2 showed no significant difference between the groups. The expression of angiogenesis factors, vascular endothelial growth factor, hepatocyte growth factor, platelet-derived growth factor, and CD31, significantly increased in the PRP+ fat transplantation group. The expression of adipogenesis factors, insulin-like growth factor 1 receptor, extracellular signal-regulated kinase, anti-CCAAT-enhancer-binding proteins, and peroxisome proliferator-activated receptor γ, also significantly increased in the PRP+ fat transplantation group.

CONCLUSIONS

The results demonstrated that PRP-combined fat transplantation attenuated dermis fibrosis and raised fat survival in the LS model by promoting angiogenesis and adipogenesis through insulin-like growth factor 1 receptor/extracellular signal-regulated kinase signaling pathway.

Regenerative vs flap-based limb salvage: a multi-centered, prospective, randomized controlled trial

Aim: The goal of this study was to compare success rates of a regenerative limb salvage approach (rLS) using dehydrated human chorion amnion membrane (dHACM) to traditional flap-based limb salvage (fLS). Materials & methods: This prospective RTC enrolled patients presenting with complex extremity wounds over a 3-year period. Primary outcomes included success of primary reconstruction, persistence of exposed structures, time to definitive closure, and time to weight bearing. Results: Patients meeting inclusion criteria were randomized to fLS (n = 14) or rLS (n = 25). The primary reconstructive method was successful for 85.7% of fLS subjects and 80% of rLS subjects (p = 1.00). Conclusion: This trial provides strong evidence that rLS is an effective option in the setting of complex extremity wounds, with success rates comparable to traditional flaps. Clinical Trial Registration: NCT03521258 (ClinicalTrials.gov).

Safety and efficacy of CO2 dot matrix laser combined with platelet-rich plasma on depressed scar after acne vulgaris and influencing factors of its repair effect: A retrospective analysis

BACKGROUND

Acne vulgaris (AV) is the most pervasive inflammatory disease of hair follicle and sebaceous gland in the dermatology department, and depressed scar (DS) is the most common and serious sequela of AV.

AIMS

To explore the clinical value of CO₂ dot matrix laser combined with platelet-rich plasma (PRP)-treated AV.

METHODS

Total 81 patients with DS at the rear of AV from December 2018 to October 2019 were selected, randomly divided into observation group (OG, n = 39) and control group (CG, n = 42). Patients in the OG group were treated with CO₂ dot matrix laser combined with PRP, and those in the CG group were treated with CO₂ dot matrix laser. To observe clinical outcomes in both groups.

RESULTS

According to experimental analysis, compared with the CG group, CO₂ dot matrix laser combined with PRP can more strongly improve the clinical efficacy on patients, shorten the scar scabbing time and decrustation time, more effectively contributed to their scar repair, comfort, skin condition, psychological state and satisfaction, and reduced their pain. The subsequent follow-up results also showed that patients in the OG group experienced better quality of life. Moreover, according to the logistic regression analysis, the course of disease, scar degree, and staying up late were independent risk factors for the repair effect, and the repair method of CO₂ dot matrix laser combined with PRP was an independent protection factor.

CONCLUSION

To sum up, CO₂ dot matrix laser combined with PRP can strongly enhance the scar repair effect, psychological state, and life quality of patients with DS after AV, so it is worth popularizing in clinical practice.

Role for platelet rich plasma as an adjuvant therapy in wound healing and burns

Background

Platelet rich plasma (PRP) contains high concentrations of growth factors. Intuitively, these were thought to be of potential benefit in healing of chronic wounds, skin grafts and graft donor sites. This was echoed in retrospective studies and an individual case basis but had not been randomized.

Methods

A systematic search was carried out by two individuals, independently, on the MEDLINE, EMBASE and COCHRANE databases, according to PRISMA guidelines. All data analysis and statistics was pooled and analysed using the Cochrane RevMan Software.

Results

Split thickness grafts have been described by numerous authors, but PRP use did not offer a significant advantage in graft take in pooled results (MD 5.83, 95% CI − 0.69 to 12.25, random-effects, p = 0.08). The analysis of included randomized controlled trials has shown favourable split-thickness skin graft donor site healing in the PRP group (MD − 5.55, 95% CI − 7.40 to − 3.69, random-effects, p =  < 0.00001) compared to the control group. For carpal tunnel syndrome, the pooled results showed no difference in functional scores vs steroid injections (SMD − 0.68, 95% CI − 1.47 to 0.10, randomeffects, p = 0.09) or indeed splinting groups.

Conclusions

With the current body of evidence, we conclude that the use of PRP as an adjuvant therapy in skin grafts, burns, carpal tunnel surgery or scars cannot be rationalised. A potential use of PRP is in donor site management but the cost of this would be difficult to justify.

Level of evidence: Not ratable.

Combination of PDGF-BB and adipose-derived stem cells accelerated wound healing through modulating PTEN/AKT pathway

Adipose-derived stem cells (ADSCs) have been widely proven to facilitate wound healing. Our study aimed to estimate the influence of combined ADSCs and platelet-derived growth factor-BB (PDGF-BB) on wound healing. We utilized 4 healthy SD rats to isolate ADSCs. Platelet-rich plasma (PRP) was acquired utilizing a two-step centrifugation technology. The role of PRP, PDGF-BB, and PDGF-BB combined with a PI3k inhibitor LY294002 on the viability, migration, and PTEN/AKT pathway in ADSCs were examined utilizing CCK-8, Transwell, and western blot assays. Then, we constructed an open trauma model in SD rats. Effects of ADSCs treated with PDGF-BB on pathological changes, CD31, and PTEN/AKT pathway of wound closure were assessed by hematoxylin & eosin (H&E) staining, Masson staining, immunohistochemical, and western blot assays, respectively. PRP and PDGF-BB intensified the viability and migration of ADSCs by modulating the PTEN/AKT pathway. Interestingly, LY294002 reversed the role of PDGF-BB on ADSCs. In vivo experiments, combined intervention with ADSCs plus PDGF-BB/PRP facilitated wound closure and ameliorated histological injury. Moreover, combined intervention with ADSCs and PDGF-BB attenuated the PTEN level and elevated the CD31 level as well as the ratio of p-AKT/AKT in the skin tissues. A combination of ADSCs and PDGF-BB facilitated wound healing might associate with the regulation of the PTEN/AKT pathway.

From Chronic Wounds to Scarring: The Growing Health Care Burden of Under- and Over-Healing Wounds

Significance: Wound healing is the largest medical market without an existing small molecule/drug treatment. Both "under-healing" (chronic wounds) and "over-healing" (scarring) cause a substantial biomedical burden and lifelong consequences for patients. These problems cost tens of billions of dollars per year in the United States alone, a number expected to grow as the population ages and the prevalence of common comorbidities (e.g., diabetes) rises. However, no therapies currently exist to produce the "ideal" healing outcome: efficient wound repair through regeneration of normal tissue. Recent Advances: Ongoing research continues to illuminate possible therapeutic avenues for wound healing. By identifying underlying mechanisms of wound repair-for instance, tissue mechanics' role in fibrosis or cell populations that modulate wound healing and scarring-novel molecular targets may be defined. This Advances in Wound Care Forum issue includes reviews of scientific literature and original research from the Hagey Laboratory for Pediatric Regenerative Medicine at Stanford and its alumni, including developing approaches for encouraging wound healing, minimizing fibrosis, and coaxing regeneration. Critical Issues: Wound healing problems reflect an enormous and rapidly expanding clinical burden. The issues of both under- and over-healing wound outcomes will continue to expand as their underlying causes (e.g., diabetes) grow. Targeted treatments are needed to enable wound repair with functional tissue restoration and decreased scarring. Future Directions: Basic scientists will continue to refine understanding of factors driving undesirable wound outcomes. These discoveries are beginning to be translated and, in the coming years, will hopefully form the foundation for antiscarring drugs and other wound therapeutics.

Autologous Fat Plus Platelet-Rich Plasma versus Autologous Fat Alone on Sulcus Vocalis

Sulcus vocalis is a frequent cause of glottic insufficiency that leads to incomplete vocal fold closure during phonation. Type II sulcus vocalis is defined as a partial defect of the lamina propria (LP). Treatment with fillers, such as fat or hyaluronic acid (HA), in the vocal folds is widely used, but the duration of effect is variable. Platelet-rich plasma (PRP) can enhance the survival of autologous fat in fat grafting, and also is used to treat sulcus vocalis. This study aimed to compare the effectiveness of autologous fat graft versus fat graft plus PRP to treat type II sulcus vocalis. Thirty-four patients with a voice handicap index (VHI) ≥ 11 were randomized to two groups, which received LP injections of fat graft (n = 17) or fat graft plus PRP (n = 17). At 1 month and 6 months after injection, the VHI decreased significantly in both groups. The fat plus PRP group had better Jitter, Shimmer, and noise to harmonic ratio (NHR) in 1 month and 6 months after surgery. The fat plus PRP group resulted in lower VHI scores one month after surgery, and stroboscopy revealed sustained smaller gaps after six months. These results indicate that a combination of fat graft plus PRP is safe and effective for treating sulcus vocalis type II and associated vocal atrophy.

Platelet-rich plasma improves lipopolysaccharide-induced inflammatory response by upgrading autophagy

Objectives

Platelet-rich plasma (PRP) plays an important role at all stages of wound healing, including the inflammatory stage. Macrophage autophagy has been found to influence the inflammatory response process. However, it is unclear whether PRP can affect inflammatory responses via macrophage autophagy. In the present study, we explored the effect of PRP on inflammatory responses and researched the underlying mechanism.

Methods

RAW 264.7 macrophages were treated with PRP and/or lipopolysaccharide (LPS). The effects of PRP on the expression of inflammatory factors were determined by ELISA and qRT-PCR. Macrophage autophagosomes were also assessed by TEM and immunofluorescence. Autophagy and NLRP3-related proteins were investigated using Western blot analysis.

Results

PRP reduced the levels of inflammatory factors and increased autophagy in RAW 264.7 cells. Pretreatment with 3-MA, which is an autophagy inhibitor, abolished the impact of PRP on the inflammatory response. Moreover, PRP induced macrophage autophagy by activating the NLRP3 inflammasome.

Conclusions

These results show that PRP can attenuate LPS-induced inflammatory responses by enhancing autophagy via NLRP3. These study also provides a new perspective on the molecular mechanism of PRP therapy in wound healing.

Chyloid Fat Carried Adipose-Derived Mesenchymal Stem Cells Accelerate Wound Healing Via Promoting Angiogenesis

ABSTRACT

Impaired wound healing is responsible for significant morbidity and mortality worldwide. It is necessary to find a stable, efficient, and safe method to promote soft tissue wound healing. Fat grafting has become increasingly popular in contouring procedures. However, more recently, there has been an emphasis on its regenerative potential. In this study, we established the wound healing model using nude mice. Hematoxylin and eosin and Masson stainings were performed to assess the effect of chyloid fat on the histology of wound healing. A laser Doppler perfusion imager was used to evaluate the blood perfusion of wounds. Immunohistochemistry was carried out to detect the expression of CD31 in wound tissues. The results suggested that after treatment with granule fat or chyloid fat, wound healing was accelerated and blood perfusion was promoted. In addition, granule fat or chyloid fat treatment promoted the angiogenesis of the wound. In addition, we evaluated the amount of adipose-derived mesenchymal stem cells in chyloid fat and granule fat. It was found that chyloid fat contained more adipose-derived mesenchymal stem cells than granule fat did. In conclusion, we proved that chyloid fat could significantly accelerate the wound healing process via promoting angiogenesis. The adipose-derived mesenchymal stem cell plays a critical role in this effect of chyloid fat.

Platelet-rich plasma enhances mechanical strength of strattice in rat model of ventral hernia repair

Incisional hernia is a common complication of hernia repair despite the development of various synthetic and bio-synthetic repair materials. Poor long-term mechanical strength, leading to high recurrence rates, has limited the use of acellular dermal matrices (ADMs) in ventral hernia repair (VHR). Biologically derived meshes have been an area of increasing interest. Still these materials bring the risk of more aggressive immune response and fibrosis in addition to the mechanical failures suffered by the synthetic materials. Platelet-rich plasma (PRP), a growth-factor-rich autologous blood product, has been shown to improve early neovascularization, tissue deposition, and to decrease the rates of recurrence. Here, we demonstrate that PRP promotes the release of growth factors stromal derived factor (SDF)-1, transforming growth factor-beta, and platelet-derived growth factor in a dose-dependent manner. Additionally, we utilize an aortic ring angiogenesis assay to show that PRP promotes angiogenesis in vitro. A rat model of VHR using StratticeTM ADM demonstrates similar findings in vivo, corresponding with the increased expression of vascular endothelial growth factor and collagen type 1 alpha 1. Finally, we show that the molecular and cellular activity initiated by PRP results in an increased mechanical stiffness of the hernia repair mesh over time. Collectively, these data represent an essential step in demonstrating the utility and the mechanism of platelet-derived plasma in biomaterial-aided wound healing and provide promising preclinical data that suggest such materials may improve surgical outcomes.

Theory and Evidence for Platelet Therapy of the Aging Face

Platelet preparations are autologous blood concentrates with supraphysiologic concentrations of platelets with or without leukocytes used in various clinical applications including regenerative medicine, wound healing, and facial rejuvenation. Their use harnesses the important role of platelets and their secretory products in immunoregulation, wound healing, angiogenesis, and tissue remodeling. The use of platelet preparations has been long documented in orthopaedic surgery, maxillofacial surgery, and other fields, but over the years research has increased in their application to facial plastic surgical techniques. Here we review the various formulations of platelet rich concentrates, their applications to facial skin rejuvenation, wound healing, scar reduction, and tissue fill as documented in the literature since 2018.

Comparison of the Effects of Repeated Applications of Platelet-Rich Plasma versus Platelet-Poor Plasma on Fat Graft Survival in Nude Mice

Autologous fat grafting has been widely used for soft tissue filling in plastic surgery. Platelet-rich plasma (PRP) could play a wide role in health and disease because of containing a variety of growth factors and cytokines. Although previous studies have described the positive effect of autologous PRP mixed with fat grafts, only minimal improvements in fat graft survival have been reported. The present study is aimed at comparing the effects of PRP and platelet-poor plasma (PPP) on the survival and quality of fat grafting. We built a 180-day nude mouse model implanted with a fat graft supplemented with PRP, PPP, or saline, respectively. The above reagents (PRP, PPP, or saline) were injected two additional times after the initial engraftment. The survival ratio of the fat grafts and the capillary density in the PRP group were significantly higher than those in the PPP group and the saline group (control group) at 15, 30, 90, and 180 days posttransplantation (P < 0.05). The survival ratio of the PPP group was higher than that of the saline group (P < 0.05), but the capillary density in the PPP group was not significantly different from that in the saline group at any time point (P > 0.05). We hence conclude that the repeated application of PRP or PPP three times can enhance the survival of fat grafts within 180 days. Moreover, the effect of PRP is superior to that of PPP.

Regenerative Wound Healing by Open Grafting of Autologous Fat and PRP-Gel - A New Concept and Potential Alternative to Flaps

Supplemental Digital Content is available in the text.

A new regenerative technique is described that enabled in situ formation of soft tissue bridge for difficult wounds, which otherwise needed flaps, resulting in complete healing in 3/3 cases. The wounds were debrided till healthy bleeding and covered with a triple-layer matrix of platelet-rich fibrin gel, condensed liposuctioned autologous fat, and porous collagen dressing. Negative pressure wound therapy was applied after 48 hours for 4–5 days in 2 cases and after 11 days for 3 weeks in the third case. Rapid vascularization was noted, with regeneration of mature tissue bridge and subsequent epithelization even over the bone. One patient underwent elective replacement of healed epithelium by split skin graft for better aesthetics and durability. This technique, if further validated, may herald a new concept of in situ regeneration, namely transformation of autologous tissue (grafted in gel form) to viable soft tissue.

Effects and mechanism of platelet-rich plasma on military drill injury: a review

Military drill injury is a significant part of military medical research. The increase of training intensity and changes in training methods lead to differences in injury types. The ideal therapeutic modality should allow rapid healing at a reasonable cost and minimize impact on patients' life. Platelet -rich plasma (PRP), a platelet concentrate, is rich in a variety of growth factors and widely used clinically as a minimally invasive treatment. It plays an important role in injury repair and rehabilitation. In this article, we review the therapeutic role of PRP in military drill injury and its possible underlying mechanisms, with a focus on plantar fasciitis, stress fractures and other common injuries, in order to provide basic support for military reserve.

The optimal platelet concentration in platelet-rich plasma for proliferation of human cells in vitro-diversity, biases, and possible basic experimental principles for further research in the field: A review

BACKGROUND

In the last decades, several in vitro studies have tested the effect of plate-rich plasma (PRP) on the proliferation of human cells in search of a wizard for the use of PRP in a clinical setting. However, the literature displays striking differences regarding this question despite the relatively similar experimental design. The aim of this review is twofold: describe and explain this diversity and suggest basic principles for further in vitro studies in the field. The optimal platelet concentration in vivo will also be discussed.

METHODS

A search in mainly EMBASE and PubMed was performed to identify in vitro studies that investigate the effect of different PRP concentrations on human cell proliferation. The assessment of bias was based on the principles of "Good Cell Culture Practice" and adapted.

RESULTS

In total, 965 in vitro studies were detected. After the initial screening, 31 studies remained for full-text screening. A total of 16 studies met the criteria of final inclusion and appeared relatively sound. In general, the studies state consistently that PRP stimulates the proliferation of the human cell. Two main types of experimental techniques were detected: 1. The Fixed PRP Concentration Group using a fixed PRP concentration throughout the experiment, which leads to a substantial decrease in nutrition available at higher concentrations. 2. The Fixed PRP Volume Group using a fixed PRP-to-media ratio (Vol/Vol) throughout the experiment. A general tendency was observed in both groups: when the PRP to media ratio increased (Vol/Vol), the proliferation rate decreased. Further, The Low Leukocyte group observed a substantial higher optimal PRP concentration than The High leukocyte group. No prominent tendencies was seen regarding anticoagulants, activation methods, and blood donor (age or sex).

DISCUSSION

Two major biases regarding optimal proliferation in vitro is pointed out: 1. Too high PRP volume. It is speculated that the techniques used by some studies led to an adverse growth condition and even cell starvation at higher concentrations. 2. High leukocyte levels. Reduced proliferation rate due to proinflammatory substances released during degranulation of leukocytes.

CONCLUSIONS

The two main biases may explain the bell-shaped effect of PRP and the detrimental effects at higher platelet concentrations observed in several studies. These biases may also explain the low optimal PRP concentration observed in some studies. Even if one universal optimal PRP concentration does not exist, the review indicates that PRP concentrations in the upper parts of the scale is optimal or at least beneficial. Finally, following basic experimental principles are suggested. 1: The PRP/media ratio (Vol/Vol) should be kept as constant. 2: The PRP/media ratio should provide a sufficient nutrition supply, that is, PRP ≤ 10% (Vol/Vol). 3: The cell density per well (cells/mL) should be defined. 4: Leukocyte level should be kept low, preferable depleted (< 0.1 PLT/µL).

A Systematic Review of Autologous Fat Grafting in the Treatment of Acute and Chronic Cutaneous Wounds

There is a growing interest in the regenerative potential of autologous fat. Adipose-derived stem cells, within the stromal vascular fraction of lipoaspirate samples, demonstrate anti-inflammatory, immunomodulatory, and angiogenic properties. This systematic review aimed to determine the efficacy and safety of autologous fat therapies for wound healing, with an evaluation of the quality of evidence provided by the literature.

A New Therapeutic Application of Platelet-Rich Plasma to Chronic Breast Wounds: A Prospective Observational Study

The aim of this study was to investigate the usefulness of platelet-rich plasma (PRP) treatment for chronic wounds (CWs) of the breast. A prospective study was performed in 23 patients with CW of the breast who were treated with PRP. The procedure was repeated until the wound was closed completely. The study included patients with a history of breast cancer (n = 8) and patients without cancer (n = 15). The treatment with PRP was successful in all cases and observed in ≤4 weeks in 82.6% (19/23) of patients. The patients without breast cancer showed significantly less time for wound closure than the patients with a history of breast cancer. Moreover, a greater number of PRP treatments were necessary to achieve wound closure in patients undergoing conservative breast treatment. No patients had complications associated with the application of PRP. Conclusions: To the best of our knowledge, this is the first study to reveal that PRP treatment for CWs of the breast is safe, simple, useful and well-tolerated by patients.

Multipotent adult progenitor cells grown under xenobiotic-free conditions support vascularization during wound healing

Background

Cell therapy has been evaluated pre-clinically and clinically as a means to improve wound vascularization and healing. While translation of this approach to clinical practice ideally requires the availability of clinical grade xenobiotic-free cell preparations, studies proving the pre-clinical efficacy of the latter are mostly lacking. Here, the potential of xenobiotic-free human multipotent adult progenitor cell (XF-hMAPC®) preparations to promote vascularization was evaluated.

Methods

The potential of XF-hMAPC cells to support blood vessel formation was first scored in an in vivo Matrigel assay in mice. Next, a dose-response study was performed with XF-hMAPC cells in which they were tested for their ability to support vascularization and (epi) dermal healing in a physiologically relevant splinted wound mouse model.

Results

XF-hMAPC cells supported blood vessel formation in Matrigel by promoting the formation of mature (smooth muscle cell-coated) vessels. Furthermore, XF-hMAPC cells dose-dependently improved wound vascularization associated with increasing wound closure and re-epithelialization, granulation tissue formation, and dermal collagen organization.

Conclusions

Here, we demonstrated that the administration of clinical-grade XF-hMAPC cells in mice represents an effective approach for improving wound vascularization and healing that is readily applicable for translation in humans.

Systematic Review-The Potential Implications of Different Platelet-Rich Plasma (PRP) Concentrations in Regenerative Medicine for Tissue Repair

The number of studies evaluating platelet-rich plasma (PRP) concentration has substantially grown in the last fifteen years. A systematic review on this field has been realized by evaluating in the identified studies the in vitro PRP concentration—also analyzing the platelet amount—and the in vivo PRP effects in tissue regeneration compared to any control. The protocol has been developed in agreement with the Preferred Reporting for Items for Systematic Reviews and Meta-Analyses-Protocols (PRISMA-P) guidelines. Multistep research of the PubMed, MEDLINE, Embase, PreMEDLINE, Ebase, CINAHL, PsycINFO, Clinicaltrials.gov, Scopus database and Cochrane databases has permitted to identify articles on different concentrations of PRP in vitro and related in vivo impact for tissue repair. Of the 965 articles initially identified, 30 articles focusing on PRP concentration have been selected and, consequently, only 15 articles have been analyzed. In total, 40% (n = 6) of the studies were related to the fixed PRP Concentration Group used a fixed PRP concentration and altered the platelet concentration by adding the different volumes of the PRP (lysate) to the culture. This technique led to a substantial decrease in nutrition available at higher concentrations. Sixty percent (n = 9) of the studies were related to the fixed PRP Volume Group that used a fixed PRP-to-media ratio (Vol/Vol) throughout the experiment and altered the concentration within the PRP volume. For both groups, when the volume of medium (nutrition) decreases, a lower rate of cell proliferation is observed. A PRP concentration of 1.0 × 10⁶ plt/μL, appears to be optimal thanks to the constant and plentiful capillary nutrition supply and rapid diffusion of growth factors that happen in vivo and it also respects the blood decree-law. The PRP/media ratio should provide a sufficient nutrition supply to prevent cellular starvation, that is, PRP ≤ 10% (Vol/Vol) and thus best mimic the conditions in vivo.

Application and prospect of adipose stem cell transplantation in treating lymphedema

BACKGROUND

Lymphedema is a chronic, debilitating and incurable disease that affects 0.13%-2% of the global population. Emerging evidence indicates that adipose-derived stem cells (ADSCs) might serve as suitable seed cells for lymphatic tissue engineering and lymphedema therapy.

AIM

To summarize applications of ADSCs for treating lymphedema in both animal studies and clinical trials.

METHODS

A systematic search was performed on four databases – PubMed, Clinicaltrials.gov, the evidence-based Cochrane Library, and OVID – using the following search string: (“lymphedema” or “lymphoedema” or “lymphangiogenesis”) and (“adipose-derived stem cells” or “adipose-derived stromal cells” or “adipose-derived regenerative cells”). A manual search was performed by skimming the references of relevant studies. Animal studies and clinical trials using adipose-derived cells for the treatment of any kind of lymphedema were included.

RESULTS

A total of eight research articles published before November 2019 were included for this analysis. Five articles focused on animal studies and another three focused on clinical trials. ADSC transplantation therapy was demonstrated to be effective against lymphedema in all studies. The animal studies found that coadministration of ADSCs and controlled-release vascular endothelial growth factor-C or platelet-rich plasma could improve the effectiveness of ADSC therapy. Three sequential clinical trials were conducted on breast cancer-related lymphedema patients, and all showed favorable results.

CONCLUSION

ADSC-based therapy is a promising option for treating lymphedema. Large-scale, multicenter randomized controlled trials are needed to develop more effective and durable therapeutic strategies.

The application of platelet-rich plasma for skin graft enrichment: A meta-analysis

Existing evidence demonstrated that the role of platelet-rich plasma (PRP) in skin graft enrichment is uncertain. The aim of this study was to evaluate the efficacy and safety of PRP for skin graft. PubMed, EMBASE, Web of Science, and Cochrane Library databases were searched for randomised controlled trials that compared outcomes of skin graft treated with PRP versus those treated with blank controls. The outcomes mainly included the rate of skin graft take, number of skin graft loss and haematoma formation, and complications. There were 11 studies involving a total of 910 cases of skin grafts. Compared with the control group, PRP group had a significantly higher rate of skin graft take (mean difference = 5.47%; 95% confidence interval [CI], 2.80%-8.14%; P < .0001), fewer number of skin graft loss (risk ratio [RR] = 0.26; 95% CI, 0.13-0.55; P = .0004) and fewer cases of haematoma formation (RR = 0.24; 95% CI, 0.11-0.54; P = .0006). There was no significant difference in the incidence of complications between two groups. This meta-analysis summarises current evidence and indicates that PRP is a safe and effective adjuvant for skin graft enrichment.

A topical cell therapy approach for diabetic chronic ulcers: Effects of mesenchymal stromal cells associated with platelet-rich plasma

BACKGROUND

Diabetic cutaneous ulcers are subjected to several physiological and biochemical defects, which contribute to wound chronicity and therapeutic failure. Platelet-rich plasma (PRP) has been used for stimulating tissue regeneration, and mesenchymal stromal cells (MSCs) have demonstrated therapeutic properties in all phases of skin regeneration in cell therapy studies.

AIMS

The objective of this study was to evaluate the therapeutic effects related to the use of a biomembrane composed of autologous MSCs and PRP on chronic wounds of diabetic patients (pre-post pilot study).

PATIENTS/METHODS

Six diabetic patients with chronic wounds for more than 6 months were subjected to adipose tissue collection for isolation of MSCs, blood collection for PRP preparation, and topical administration of a biomembrane of MSCs and PRP on each chronic wound. The statistical difference regarding the evolution of ulcers was calculated by means of paired t test.

RESULTS

There was granulation tissue formation starting from 7 days after topical application. Total re-epithelialization occurred in 5 of the 9 lesions treated, and the mean wound healing rate (WHR) was 74.55% (±32.55%) after 90 days. No cicatricial hypertrophy or retraction was observed.

CONCLUSION

Mesenchymal stromal cells topical therapy associated with PRP is well-tolerated and able to provide a reduction in ulcer area of diabetic chronic wounds.

Photoaging Skin Therapy with PRP and ADSC: A Comparative Study

BACKGROUND

Stem cells from adipose tissue (ADSCs) and platelet-rich plasma (PRP) are innovative modalities that arise due to their regenerative potential.

OBJECTIVE

The aim of this study was to characterize possible histological changes induced by PRP and ADSC therapies in photoaged skin.

METHODS

A prospective randomized study involving 20 healthy individuals, showing skin aging. They underwent two therapeutic protocols (protocol 1: PRP; protocol 2: ADSCs). Biopsies were obtained before and after treatment (4 months).

RESULTS

PRP protocol showed unwanted changes in the reticular dermis, mainly due to the deposition of a horizontal layer of collagen (fibrosis) and elastic fibers tightly linked. Structural analyses revealed infiltration of mononuclear cells and depot of fibrotic material in the reticular dermis. The ADSC protocol leads to neoelastogenesis with increase of tropoelastin and fibrillin. There was an improvement of solar elastosis inducing an increment of macrophage polarization and matrix proteinases. These last effects are probably related to the increase of elastinolysis and the remodeling of the dermis.

CONCLUSIONS

The PRP promoted an inflammatory process with an increase of reticular dermis thickness with a fibrotic aspect. On the other hand, ADSC therapy is a promising modality with an important antiaging effect on photoaged human skin.

Autologous Fat Grafting Promotes Macrophage Infiltration to Increase Secretion of Growth Factors and Revascularization, Thereby Treating Diabetic Rat Skin Defect

BACKGROUND

Diabetic skin defect is difficult to manage in surgical clinics, and there is still lack of effective treatments for diabetic skin defects. Currently, autologous fat grafting (AFG) is promising in the field of reconstructive surgery, while macrophage infiltration in autologous adipose tissue is considered vital for tissue regeneration. But AFG is rarely applied to the treatment of diabetic skin defects, and whether macrophage infiltration assists AFG to promote wound healing is still unknown.

METHODS

Full-thickness skin defect diabetic rats were divided into 3 groups: control group, autologous fat grafting (AFG) group and AFG with macrophage depletion (AFG+MD) group. We examined the amount of macrophages in the wounds bed and the expression level of inflammatory factors IL-10, IL-6, TNF-α, and also growth factors PDGF-β, TGF-β, IGF-1 at the same time. The content of collagen-I and α-smooth muscle actin protein in the wounds were determined by Western blot analysis. Finally, the healing of the wounds was evaluated.

RESULTS

The AFG group showing more rapid healing, secreting more growth factors and more obvious vascularization in the healing process, compared with the control group. But, the secretion of growth factors and the construction of extracellular matrix (ECM) in the wounds were limited when macrophages were depleted after AFG.

CONCLUSION

AFG promotes the infiltration of macrophages to improve the healing environment of diabetic wounds by increasing the secretion of growth factors and revascularization, which provides a potential method for the treatment of diabetic skin defects.

Synergistic Effects of Human Platelet-Rich Plasma Combined with Adipose-Derived Stem Cells on Healing in a Mouse Pressure Injury Model

Pressure injury (PI) affects quality of life and results in economic and social burdens. Local transplantation of human adipose-derived stem cells (ASCs) is considered an effective treatment. However, ASC suspension alone is vulnerable to the immune system and results in a shortened cell survival. There is increasing evidence of a synergistic effect of platelet-rich plasma (PRP) combined with ASCs on wound healing. This study investigated the effectiveness, synergy, and mechanism of wound healing following local injection of PRP combined with ASCs in a rodent PI model. PRP or ASCs alone were the control intervention. Wound healing, inflammatory infiltration, collagen deposition, angiogenesis, neurogenesis, and cell homing were investigated. PI healing was promoted by the synergistic effects of PRP combined with ASCs. The combination was more effective than ASCs alone for modulating inflammation, increasing collagen deposition, angiogenesis, neurogenesis, and the persistence of the injected ASCs. These data provide a theoretical foundation for the clinical administration of ASCs combined with PRP in PI healing and skin regeneration.

Advances in surgical applications of growth factors for wound healing

Growth factors have recently gained clinical importance for wound management. Application of recombinant growth factors has been shown to mimic cell migration, proliferation, and differentiation in vivo, allowing for external modulation of the healing process. Perioperative drug delivery systems can enhance the biological activity of these growth factors, which have a very short in vivo half-life after topical administration. Although the basic mechanisms of these growth factors are well understood, most have yet to demonstrate a significant impact in animal studies or small-sized clinical trials. In this review, we emphasized currently approved growth factor therapies, including a sustained release system for growth factors, emerging therapies, and future research possibilities combined with surgical procedures. Approaches seeking to understand wound healing at a systemic level are currently ongoing. However, further research and consideration in surgery will be needed to provide definitive confirmation of the efficacy of growth factor therapies for intractable wounds.

The use of fat grafting and platelet-rich plasma for wound healing: A review of the current evidence

Fat grafting is becoming a common procedure in regenerative medicine because of its high content of growth factors and adipose derived stem cells (ADSCs) and the ease of harvest, safety, and low cost. The high concentration of ADSCs found in fat has the potential to differentiate into a wide range of wound-healing cells including fibroblasts and keratinocytes as well as demonstrating proangiogenic qualities. This suggests that fat could play an important role in wound healing. However retention rates of fat grafts are highly variable due in part to inconsistent vascularisation of the transplanted fat. Furthermore, conditions such as diabetes, which have a high prevalence of chronic wounds, reduce the potency and regenerative potential of ADSCs. Platelet-rich plasma (PRP) is an autologous blood product rich in growth factors, cell adhesion molecules, and cytokines. It has been hypothesised that PRP may have a positive effect on the survival and retention of fat grafts because of improved proliferation and differentiations of ADSCs, reduced inflammation, and improved vascularisation. There is also increasing interest in a possible synergistic effect that PRP may have on the healing potential of fat, although the evidence for this is very limited. In this review, we evaluate the evidence in both in vitro and animal studies on the mechanistic relationship between fat and PRP and how this translates to a benefit in wound healing. We also discuss future directions for both research and clinical practice on how to enhance the regenerative potential of the combination of PRP and fat.