Effect of platelet-rich plasma on polypropylene meshes implanted in the rabbit vagina: histological analysis

The Emerging Role on the Use of Platelet-Rich Plasma Products in the Management of Urogynaecological Disorders

Background: The regenerative efficacy of platelet-derived products has been recently investigated in the treatment of pelvic floor disorders (PFDs). We aimed to synthesize the current evidence of platelet-rich plasma (PRP) products used in urogynaecological disorders including vaginal atrophy, pelvic organ prolapse (POP), urinary incontinence, vaginal fistulas and vaginal mesh exposure. Methods: A meticulous search of the currently available literature on the use of PRP for the management of PFDs was performed using 3 electronic databases. Results: PRP could be a feasible alternative modality for the management of vaginal atrophy with favourable outcomes in vaginal atrophy parameters and patients' satisfaction, especially when hormone therapy is contraindicated. In patients with POP, an increase in collagen concentration after PRP application was observed while the use of PRP resulted in improvement of stress urinary incontinence symptoms. A considerable proportion of vesicovaginal fistulas were treated after application of PRP-based injections. Conclusions: There is only limited evidence of the use of PRP for PFDs. Platelet-rich plasma appears to be a promising, easy to apply, cost-effective and feasible alternative therapeutic modality for the management of various urogynaecological disorders. Future randomized trials are needed to confirm the efficacy of PRP in the treatment of urogynaecological disorders.

Bioinspired Hydrogel Coating Based on Methacryloyl Gelatin Bioactivates Polypropylene Meshes for Abdominal Wall Repair

Considering the potential of hydrogels to mimic the cellular microenvironment, methacryloyl gelatin (GelMA) and methacryloyl mucin (MuMA) were selected and compared as bioinspired coatings for commercially available polypropylene (PP) meshes for ventral hernia repair. Thin, elastic hydrated hydrogel layers were obtained through network-forming photo-polymerization, after immobilization of derivatives on the surface of the PP fibers. Fourier transform infrared spectroscopy (FTIR) proved the successful coating while the surface morphology and homogeneity were investigated by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). The stability of the hydrogel layers was evaluated through biodynamic tests performed on the coated meshes for seven days, followed by inspection of surface morphology through SEM and micro-CT. Taking into account that platelet-rich plasma (PRP) may improve healing due to its high concentration of growth factors, this extract was used as pre-treatment for the hydrogel coating to additionally stimulate cell interactions. The performed advanced characterization proved that GelMA and MuMA coatings can modulate fibroblasts response on PP meshes, either as such or supplemented with PRP extract as a blood-derived bioactivator. GelMA supported the best cellular response. These findings may extend the applicative potential of functionalized gelatin opening a new path on the research and engineering of a new generation of bioactive meshes.

Stress Urinary Incontinence and Pelvic Organ Prolapse: Biologic Graft Materials Revisited

Symptomatic stress urinary incontinence (SUI) and pelvic organ prolapse (POP) refractory to conservative management with pelvic floor muscle training or vaginal pessaries may warrant surgical intervention with different forms of biologic or synthetic material. However, in recent years, several global regulatory agencies have issued health warnings and recalled several mesh products due to an increase in complications such as mesh erosion, infection, chronic pain, and perioperative bleeding. At present, current surgical treatment strategies for SUI and POP are aimed at developing biological graft materials with similar mechanical properties to established synthetic meshes, but with improved tissue integration and minimal host response. This narrative review aims to highlight recent studies related to the development of biomimetic and biologic graft materials as alternatives to traditional synthetic materials for SUI/POP repair in female patients. We also investigate complications and technical limitations associated with synthetic mesh and biological biomaterials in conventional SUI and POP surgery. Our findings demonstrate that newly developed biologic grafts have a lower incidence of adverse events compared to synthetic biomaterials. However there remains a significant disparity between success in preclinical trials and long-term clinical translation. Further characterization on the optimal structural, integrative, and mechanical properties of biological grafts is required before they can be reliably introduced into clinical practice for SUI and POP surgery. Impact statement Our review article aims to outline the clinical history of developments and controversies associated with the use of synthetic mesh materials in the surgical treatment of stress urinary incontinence and pelvic organ prolapse, as well as highlighting recent advancements in the area of biological graft materials and their potential importance in an area that remains an enduring issue for patients and clinicians alike. This article aims to provide a concise summary of previous controversies in the field of urinary incontinence, while evaluating the future of potential biomaterials in this field.

The importance of developing relevant animal models to assess existing and new materials

PURPOSE OF REVIEW

We summarize the recent literature on the use of different animal models for testing existing and new materials for treatment of pelvic organ prolapse.

RECENT FINDINGS

A wide spectrum of animal models is being used in urogynecology, both for the study of physiologic and pathophysiologic processes, training in surgical procedures, yet mainly to study the host response to implant materials. The quality of studies is variable, and procedures, read-outs, and reporting are not standardized. This makes comparison very difficult. The research community is experimenting with different knitting patterns, novel polymers, bioactivation, as well as resorbable rather than durable implants. Outcomes of the experiments are dependent on the location of implantation. Lighter polypropylene constructs seem to induce a less vigorous host response than elder heavier products. Modification of the surface yields contradictory findings. Resorbable acellular collagen matrices may be reintroduced as prophylactically inserted support structures.

SUMMARY

Although animal experimentation with novel candidate implants is advocated, there is a lack of standardization in reporting. The concept of resorbable construct is being revived, as durable materials have caused clinical graft-related complications. Large animal experiments seem to provide interesting and more comprehensive information, yet their use may be contested.

Platelet-rich plasma administration to the lower anterior vaginal wall to improve female sexuality satisfaction

Objective:

To investigate the effect of platelet-rich plasma (PRP) injection to the lower one-third of the anterior vaginal wall on sexual function, orgasm, and genital perception in women with sexual dysfunction.

Materials and Methods:

Four sessions of PRP were administered to the anterior vaginal wall of 52 female patients with sexual dysfunction and orgasmic disorder [Female Sexual Function Index (FSFI) total score ≤26 orgasmic subdomain score ≤3.75]. Prior to the PRP administrations in each session, the FSFI validated in Turkish, the Female Genital Self-Image Scale (FGSIS), the Female Sexual Distress Scale-Revised (FSDS-R), and Rosenberg’s Self-Esteem Scale were used and in the final follow-up, and the Patient Global Impression of Improvement (PGI-I) was performed and the results were analyzed.

Results:

Following the application of the PRP, the total FSFI score was observed as 27.88±4.80 and the total score was 26 and above in 50% of the patients (p<0.001). Orgasm subdomain scores were found as 2.11±1.20 before the PRP treatment and 4.48±1.14 afterwards (p<0.001). A significant change was observed in all sub-domains after PRP and it was observed that this change started after the first administration (p<0.001). A statistically significant increase was determined in FGSIS genital perception scores, which was significant between the 1^st and 2^nd months (p<0.001). The FSDS-R scores showed a minimal increase in stress scores as the application number increased, but a statistically significant decrease was observed in the 4th administration (p<0.001). No statistically significant difference was found in Rosenberg Scale scores before and after treatment (p=0.389). High satisfaction was found in PGI-I scores.

Conclusion:

As a minimally invasive method, PRP administration to the distal anterior vaginal wall may improve female sexuality with high satisfaction.

Effect of the platelet-rich plasma covering of polypropylene mesh on oxidative stress, inflammation, and adhesions

INTRODUCTION AND HYPOTHESIS

Polypropylene mesh (PPM) is often used for urogynecological repair; however, it can cause complications. An approach to reduce complications is to coat PPM with anti-inflammatory and wound-healing molecules. Platelet-rich plasma (PRP) is inexpensive and improves wound healing. Therefore, we evaluated whether covering PPM with PRP could reduce inflammation, adhesion, and oxidative stress (OS) in rabbits.

METHODS

The primary objective was to evaluate OS, and the secondary objectives were to evaluate inflammation and adhesion. PRP-coated PPM was implanted on the right side of the abdominal cavity of 12 female New Zealand rabbits, in the interface between the hypodermis and peritoneum. An uncoverated PPM was implanted in the other side. Twelve rabbits served as the sham group; all animals were euthanized after 30 or 60 days. Inflammatory parameters were myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) activities. OS was evaluated by measuring the ferric-reducing antioxidant power, the free-radical-reducing ability of 3-ethylbenzothiazoline-6-sulfonic acid [2,2'-azino-bis (ABTS)], reduced glutathione levels, and superoxide anion production. Adhesion was measured using tenacity and Diamond scales (the latter of which grades adhesions according to their extent) Inflammation and OS were analyzed by analysis of variance (ANOVA), followed by Tukey's test. The Mann-Whitney test was used to evaluate adhesions, and analysis of the sham group was conducted using Kruskal-Wallis test.

RESULTS

No significant differences were observed in parameters of adhesions. After 60 days, PRP-coverated PPM presented a decrease in MPO and NAG activities. Furthermore, decreased OS and increased antioxidant levels were observed in PRP-coverated PPM samples.

CONCLUSIONS

The reduction of OS and inflammatory responses indicates that PRP-covered PPM is a promising therapeutic approach.

The challenge of stress incontinence and pelvic organ prolapse: revisiting biologic mesh materials

PURPOSE OF REVIEW

The present article reviews the history of mesh-related complications and regulations in SUI and POP repair settings, clinical outcomes associated with the use of biologic and synthetic mesh materials, and novel approaches using modified mesh materials.

RECENT FINDINGS

Treatment of pelvic floor disorders, such as stress urinary incontinence (SUI) and pelvic organ prolapse (POP) commonly involves implantation of synthetic surgical mesh materials like polypropylene. Many synthetic mesh materials, however, are associated with a foreign body response upon implantation, which is characterized by fibrotic encapsulation. Complications, including erosion, infections, bleeding, and chronic pain, have led to warnings by regulatory agencies and the recall of several mesh products. To mitigate such complications, biologic mesh materials have been proposed as alternatives for SUI and POP repair.

SUMMARY

Clinical outcomes of surgical repair of POP/SUI are similar between biologic and synthetic meshes, but biologic meshes have a lower incidence of adverse effects. Several strategies for modifying or functionalizing biological and synthetic meshes have shown promising results in preclinical studies.

Meshes in a mess: Mesenchymal stem cell-based therapies for soft tissue reinforcement

Surgical meshes are frequently used for the treatment of abdominal hernias, pelvic organ prolapse, and stress urinary incontinence. Though these meshes are designed for tissue reinforcement, many complications have been reported. Both differentiated cell- and mesenchymal stem cell-based therapies have become attractive tools to improve their biocompatibility and tissue integration, minimizing adverse inflammatory reactions. However, current studies are highly heterogeneous, making it difficult to establish comparisons between cell types or cell coating methodologies. Moreover, only a few studies have been performed in clinically relevant animal models, leading to contradictory results. Finally, a thorough understanding of the biological mechanisms of mesenchymal stem cells in the context of foreign body reaction is lacking. This review aims to summarize in vitro and in vivo studies involving the use of differentiated and mesenchymal stem cells in combination with surgical meshes. According to preclinical and clinical studies and considering the therapeutic potential of mesenchymal stem cells, it is expected that these cells will become valuable tools in the treatment of pathologies requiring tissue reinforcement. STATEMENT OF SIGNIFICANCE: The implantation of surgical meshes is the standard procedure to reinforce tissue defects such as hernias. However, an adverse inflammatory response secondary to this implantation is frequently observed, leading to a strong discomfort and chronic pain in the patients. In many cases, an additional surgical intervention is needed to remove the mesh. Both differentiated cell- and stem cell-based therapies have become attractive tools to improve biocompatibility and tissue integration, minimizing adverse inflammatory reactions. However, current studies are incredibly heterogeneous and it is difficult to establish a comparison between cell types or cell coating methodologies. This review aims to summarize in vitro and in vivo studies where differentiated and stem cells have been combined with surgical meshes.

ORIGINAL EFFECTIVE, SAFE TECHNIQUE OF OBTAINING PLATELET RICH PLASMA BY CENTRIFUGATION OF THE BLOOD PLASMA IN MODIFIED SYRINGE CONTAINERS

The aim: to develop, substantiate an effective and safe technology for producing PRP (platelet rich plasma). To quantify the substrate based on the recommended centrifugation protocols. Materials and methods: the effectiveness of the original harvesting protocol was evaluated by quantifying the number of platelets. The proposed technique is formed basing on the basic principles of double centrifugation of whole blood in test tubes with anticoagulant, separation with the release of a plasma layer with a high content of platelets. The centrifuging mode for quantifying the effectiveness of the substrate was selected according to recommendations based on a study confirming maximum efficiency (160g×10min + 250g×15min). For quantitative evaluation, blood was collected from 10 healthy volunteers (7 men, 3 women) with an average age of 26.0±2.6, and centrifuged in standard mode. Quantitative evaluation of platelets of whole blood and the obtained PRP substrate was carried out with a semi-automatic analyzer. Results: the proposed technique is based on the use as a container for centrifuging a syringe with a LuerLock design, which is hermetically sealed with a congruent plug, adapted by the external size of the centrifuge rotor bowl. Phase selection after centrifugation was performed by aspiration of the syringe contents after centrifugation is performed through a three-way valve. The substrate was obtained by repeated centrifugation of the contents, which allows obtaining a variable volume and platelet concentration in PRP. The amount of platelets (PLT) of whole blood is 227.0±57.0 thousand per ml. PLT PRP 945.0±279.0 thousand per ml. Conclusions: the proposed method of separation of whole blood with the release of the platelet rich plasma demonstrates high efficiency, which corresponds to the level of increasing the number of platelets in reducing the volume at the level of the best ready-made solutions. The equipment is economical and does not require highly specialized equipment and consumables. The proposed technique provides a wide choice to the performer in the received volume of the substrate.