The prophylactic effects of platelet-leucocyte gel in osteomyelitis: an experimental study in a rabbit model

Platelet-rich plasma attenuates the UPEC-induced cystitis via inhibiting MMP-2,9 activities and downregulation of NGF and VEGF in Canis Lupus Familiaris model

One of the most prevalent disorders of the urinary system is urinary tract infection, which is mostly brought on by uropathogenic Escherichia coli (UPEC). The objective of this study was to evaluate the regenerative therapeutic and antibacterial efficacy of PRP for induced bacterial cystitis in dogs in comparison to conventional antibiotics. 25 healthy male mongrel dogs were divided into 5 groups (n = 5). Control negative group that received neither induced infection nor treatments. 20 dogs were randomized into 4 groups after two weeks of induction of UPEC cystitis into; Group 1 (control positive; G1) received weekly intravesicular instillation of sodium chloride 0.9%. Group 2 (syst/PRP; G2), treated with both systemic intramuscular antibiotic and weekly intravesicular instillation of PRP; Group 3 (PRP; G3), treated with weekly intravesicular instillation of PRP, and Group 4 (syst; G4) treated with an intramuscular systemic antibiotic. Animals were subjected to weekly clinical, ultrasonographic evaluation, urinary microbiological analysis, and redox status biomarkers estimation. Urinary matrix metalloproteinases (MMP-2, MMP-9) and urinary gene expression for platelet-derived growth factor -B (PDGF-B), nerve growth factor (NGF), and vascular endothelial growth factor (VEGF) were measured. At the end of the study, dogs were euthanized, and the bladder tissues were examined macroscopically, histologically, and immunohistochemically for NF-κB P65 and Cox-2. The PRP-treated group showed significant improvement for all the clinical, Doppler parameters, and the urinary redox status (p < 0.05). The urinary MMPs activity was significantly decreased in the PRP-treated group and the expression level of urinary NGF and VEGF were downregulated while PDGFB was significantly upregulated (p < 0.05). Meanwhile, the urinary viable cell count was significantly reduced in all treatments (P < 0.05). Gross examination of bladder tissue showed marked improvement for the PRP-treated group, expressed in the histopathological findings. Immunohistochemical analysis revealed a marked increase in Cox-2 and NF-κB P65 in the PRP-treated group (P < 0.05). autologous CaCl2-activated PRP was able to overcome the bacterial infection, generating an inflammatory environment to overcome the old one and initiate tissue healing. Hence, PRP is a promising alternative therapeutic for UPEC cystitis instead of conventional antibiotics.

Chondroprotective Effects of Chondrogenic Differentiated Adipose-Derived Mesenchymal Stem Cells Sheet on Degenerated Articular Cartilage in an Experimental Rabbit Model

Adipose-derived stem cells (ADSCs) have been studied for many years as a therapeutic option for osteoarthritis (OA); however, their efficacy remains insufficient. Since platelet-rich plasma (PRP) induces chondrogenic differentiation in ADSCs and the formation of a sheet structure by ascorbic acid can increase the number of viable cells, we hypothesized that the injection of chondrogenic cell sheets combined with the effects of PRP and ascorbic acid may hinder the progression of OA. The effects of induction of differentiation by PRP and formation of sheet structure by ascorbic acid on changes in chondrocyte markers (collagen II, aggrecan, Sox9) in ADSCs were evaluated. Changes in mucopolysaccharide and VEGF-A secretion from cells injected intra-articularly in a rabbit OA model were also evaluated. ADSCs treated by PRP strongly chondrocyte markers, including type II collagen, Sox9, and aggrecan, and their gene expression was maintained even after sheet-like structure formation induced by ascorbic acid. In this rabbit OA model study, the inhibition of OA progression by intra-articular injection was improved by inducing chondrocyte differentiation with PRP and sheet structure formation with ascorbic acid in ADSCs.

Antibacterial Properties of Canine Platelet-Rich Plasma and Other Non-Transfusional Hemo-Components: An in vitro Study

This in vitro study was carried out to evaluate the potential antibacterial properties of canine non-transfusional hemo-components. Therapeutic formulations commonly used for regenerative medicine purposes (platelet-rich plasma, platelet gel, platelet lysate, fibrin glue), considering both leukocyte-rich and leukocyte-poor formulations, but also platelet-poor plasma and activating substances (thrombin, calcium gluconate), were tested to detect elements with potential antimicrobial properties. The antibacterial effect was tested on different bacterial strains (Staphylococcus aureus subspecies aureus, Staphylococcus cohnii subspecies cohnii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae subspecies pneumoniae) isolated from canine wounds and classified as susceptible, multidrug-, extensively, and pandrug-resistant bacteria toward a known panel of human and veterinary antibiotics. The evaluation was carried out by agar gel diffusion method (Kirby-Bauer) and micro-inhibition in broth using microplates and spectrophotometer reading. The study findings confirmed the hypothesized antibacterial properties of canine non-transfusional hemo-components. A more effective bacteriostatic effect was found against Gram-negative bacteria, drug-resistant too. The presence of leukocytes or platelets does not appear to be essential for the antibacterial effect. Further studies should be conducted to evaluate the exact mechanism of action of the antimicrobial activity. However, non-transfusional hemo-components could be a useful natural aid in controlling bacterial infections in dogs.

Platelet Rich Plasma in Orthopedic Surgical Medicine

There is a global interest in optimizing post-surgical tissue repair strategies, leading to better patient outcomes and fewer complications, most ideally with reduced overall cost. In this regard, in recent years, the interest in autologous biological treatments in orthopedic surgery and sports medicine has increased greatly, and the addition of platelet-rich plasma (PRP) to the surgical armamentarium is of particular note. Unfortunately, the number of PRP preparation devices has also grown immensely over the recent decades, raising meaningful concern for the considerable variation in the qualities of currently available PRP preparations. The lack of consensus on the standardization of PRP preparation and of agreement on condition specific PRP formulations is largely responsible for the sometimes contradictory outcomes in the literature. Furthermore, the full potential of PRP technology, the concept of individualized treatment protocols based on bioformulation options, and platelet dosing, angiogenesis, and antimicrobial and painkilling effects of PRP relevant to orthopedic surgery have rarely been addressed. In this review, we will discuss recent developments regarding PRP preparations and potential therapeutic effects. Additionally, we present a synopsis of several published data regarding PRP applications in orthopedic surgery for treating tendon injuries, inducing bone repair, strengthening spinal fusion outcomes, and supporting major joint replacements.

The influence of leukocyte-platelet-rich plasma on accelerated orthodontic tooth movement in rabbits

Objective

To determine the effects of a local injection of leukocyte-platelet-rich plasma (L-PRP) on orthodontic tooth movement in rabbits.

Methods

Twenty-three male New Zealand white rabbits were included in a split-mouth design. Tooth movement with a 100-g nickel-titanium closed-coil spring was performed on the maxillary first premolars. L-PRP was injected submucosally at the buccal and lingual areas of the first premolar in one random side of the maxilla and the other side served as the control and received normal saline. The amount of tooth movement was assessed on three-dimensional digital models on days 0, 3, 7, 14, 21, and 28. Histological findings and osteoclast numbers were examined on day 0 as the baseline and on days 7, 14, and 28.

Results

The L-PRP group showed significantly greater cumulative tooth movement at all observed periods. However, a significantly higher rate of tooth movement was observed only on days 0–7 and 7–14. The osteoclast numbers were significantly increased in the L-PRP group on days 7 and 14.

Conclusions

Local injection of L-PRP resulted in a transient increase in the rate of tooth movement and higher osteoclast numbers.

Effects of Leukocyte-Platelet-Rich Plasma on the Alveolar Bone Changes During Orthodontic Tooth Movement in Rabbits: A Micro-CT Study

Objective: To investigate the effects of leukocyte-platelet-rich plasma (L-PRP) on the alveolar bone changes at the compression and tension sides during orthodontic tooth movement.

Materials and Methods: Around 20 New Zealand white rabbits were used in a split-mouth design. The maxillary first premolar was moved mesially with a nickel-titanium closed-coil spring. One side of the maxilla was randomly injected with L-PRP, while the contralateral side served as the control which received normal saline. The alveolar bone adjacent to the maxillary first premolar was scanned using microcomputed tomography at days 0, 7, 14, and 28. Microstructural parameters including bone volume fraction, trabecular thickness, and trabecular separation of alveolar bone were assessed on the compression and tension sides of the maxillary first premolar.

Results: Compared between the groups, the L-PPR group showed a significantly decreased bone volume fraction on the compression side on days 7 and 14 but significantly increased bone volume fraction on the tension side on day 14. However, there were no statistically significant differences in the parameters of trabecular thickness and trabecular separation.

Conclusion: Local administration of L-PRP may promote bone resorption on the compression side and bone formation on the tension side at the initial stage of orthodontic tooth movement.

Platelet-Rich Plasma for the Treatment of Tissue Infection: Preparation and Clinical Evaluation

IMPACT STATEMENT

The clinical application of platelet-rich plasma (PRP) has been widely studied for its effects on trauma or injury repair/regeneration, however the antibacterial property of PRP has been overlooked. Increasing evidence suggests PRP as a good antibacterial agent and that it could help prevent/treat tissue infection. This review emphasizes the importance of PRP's antibacterial property and summarizes the preclinical and clinical findings regarding the application of PRP in the prevention and treatment of wound and bone infection. The use of biocompatible PRP may be advantageous for tissue infection treatment due to its inherent antibacterial and healing promoting properties.

Animal models of orthopaedic infections. A review of rabbit models used to induce long bone bacterial infections

The development of infections is one of the main complications in orthopaedics, especially in the presence of implants for the osteosynthesis of compound fractures and joint prosthesis. Indeed, foreign materials and implants act as substrates for the adhesion and proliferation of bacterial strains able to produce biofilm, causing peri-implant osteomyelitis. The eradication of biofilm remains a great challenge for the host immune system, as well as for medical and surgical approaches, thus imposing the need for new prophylactic and/or therapeutic strategies in which animal models have an essential role. In vivo orthopaedic models have mainly been used to study the pathogenesis of infections, biofilm behaviour and the efficacy of antimicrobial strategies, to select diagnostic techniques and test the efficacy of novel materials or surface modifications to impede both the establishment of bone infections and the associated septic loosening of implants. Among several models of osteomyelitis and implant-related infections described in small rodents and large animals, the rabbit has been widely used as a reliable and reproducible model of orthopaedic infections. This review examines the relevance of rabbits for the development of clinically representative models by analysing the pros and cons of the different approaches published in the literature. This analysis will aid in increasing our knowledge concerning orthopaedic infections by using this species. This review will be a tool for researchers who need to approach pre-clinical studies in the field of bone infection and have to identify the most appropriate animal model to verify their scientific hypothesis.

Pure platelet-rich plasma and supernatant of calcium-activated P-PRP induce different phenotypes of human macrophages

AIM

This study aimed to evaluate the effect of two platelet preparations used in the clinic, pure platelet-rich plasma (P-PRP) and the supernatant of calcium-activated P-PRP (S-PRP), on the phenotype of human macrophages.

MATERIALS & METHODS

Surface markers and cytokine production of human monocyte-derived macrophages were analyzed after 24 h stimulation with P-PRP or S-PRP.

RESULTS

P-PRP and S-PRP present no difference in the expression of CD206, a M2 tissue-repair macrophage-related marker. However, these same macrophages presented different levels of CD163, CD86 as well as different IL-10 secretion capacities after 24 h incubation.

CONCLUSION

These platelet preparations do not have an equivalent biological effect over macrophages, which suggest that they may present different clinical regenerative potentials.

Treatment of endo-periodontal lesion using leukocyte-platelet-rich fibrin. A case report

Case Description:

The main objective of this paper was to report the clinical effectiveness of leukocyte- platelet- rich fibrin (L-PRF) in the treatment of a combined endo-periodontal lesion of an upper first premolar.

Clinical Findings:

The tooth had a profound abfraction on the vestibular aspect and presented no mobility but revealed a deep pocket measuring of 11 mm on the mesial vestibular aspect and 14 mm on the mesial palatine aspect. The three dimensional image analysis showed total bone loss in the mesial aspect and an extensively bone loss of the vestibular aspect of the vestibular root.

Treatment and Outcome:

Endodontic treatment was performed and periodontal access surgery (surgical periodontal therapy) was done with the application of autologous L-PRF. Three month and 6 months after surgery, the cone beam computed tomography (CBCT) exams showed no bone regeneration in any aspect of the tooth. However, periodontal examination showed a significative improvement in the deepness of surcus. The mesial vestibular aspect had a deep pocket of 3 mm and 5 mm on the mesial palatine aspect showing a reduction in deepness of 8 mm and 9 mm, respectively.

Clinical Relevance:

The actual treatment for teeth with bad prognosis is the extraction and replacement with implants. Even though implants are capable of restore function and aesthetic, the abuse of this approach have led to the loss of teeth that could be successfully treated with a less invasive technique. The prognosis of teeth with endoperiodontal lesion is poor but could be enhanced with regenerative therapies. Until now there are no clinical trials and just four case report about the treatment of these teeth with platelet rich fibrin.

Evaluation of Platelet-Rich Plasma and Neutrophil Antimicrobial Extract as Two Autologous Blood-Derived Agents

The platelet-rich plasma (PRP) and antimicrobial peptides neutrophil extract (AMP extract) were prepared from rabbit neutrophils as two autologous blood-derived preparations, which could be applied locally to enhance healing process of tissues. Both preparations were analyzed using the MALDI TOF method for accurate qualitative assay. Growth factors (PDGF and VEGF) and microbicidal protein were reported in PRP. In AMP extract α-defensins, namely; NP-1, -2, -3a, -3b, -4, and -5 and cathelicidins represented among other by 15-kDa antibacterial protein (p15s) were detected. In the second part of our study the influence of antimicrobial extract on macrophages in vitro was tested. Then, degranulation of neutrophils in vitro and generation of reactive intermediates by these cells under the influence of AMP extract were assessed. As estimated, the addition of AMP extract into cultures of macrophages decreased superoxide anion generation after 5 days of incubation. Furthermore, AMP extract inhibited degranulation and respiratory burst in neutrophils, therefore in this regard it suppress proinflammatory effect of two studied populations of leukocytes.

Comparative evaluation of leukocyte- and platelet-rich plasma and pure platelet-rich plasma for cartilage regeneration

Platelet-rich plasma (PRP) has gained growing popularity in the treatment of articular cartilage lesions in the last decade. However, the potential harmful effects of leukocytes in PRP on cartilage regeneration have seldom been studied in vitro, and not at all in vivo yet. The objective of the present study is to compare the effects of leukocyte- and platelet-rich plasma (L-PRP) and pure platelet-rich plasma (P-PRP) on cartilage repair and NF-κB pathway, in order to explore the mechanism underlying the function of leukocytes in PRP in cartilage regeneration. The constituent analysis showed that P-PRP had significantly lower concentrations of leukocytes and pro-inflammatory cytokines compared with L-PRP. In addition, cell proliferation and differentiation assays indicated P-PRP promoted growth and chondrogenesis of rabbit bone marrow mesenchymal stem cells (rBMSC) significantly compared with L-PRP. Despite similarity in macroscopic appearance, the implantation of P-PRP combining rBMSC in vivo yielded better cartilage repair results than the L-PRP group based on histological examination. Importantly, the therapeutic effects of PRP on cartilage regeneration could be enhanced by removing leukocytes to avoid the activation of the NF-κB pathway. Thus, PRP without concentrated leukocytes may be more suitable for the treatment of articular cartilage lesions.

Platelet-rich plasma, bilayered acellular matrix grafting and negative pressure wound therapy in diabetic foot infection

Management and treatment of acute severe diabetic foot disease in patients with suboptimal glycaemic control is a critical issue in wound repair. This paper discusses the clinical efficacy of an aggressive surgical intervention combined with targeted use of regenerative medical therapies in limb preservation. Negative pressure wound therapy (NPWT), platelet-rich plasma (PRP), bilayered acellular matrix grafting and split-thickness skin grafting were combined to treat a patient with diabetes, foot necrotising fasciitis and gaseous gangrene. The wound was completely healed. The clinical outcome revealed that a multi-intervention strategy could be effective for large necrotising fasciitis wounds. Early clinical observation, suggests aggresive surgical intervention preserving intact tissue and targeted use of new regenerative technologies can lead to preservation of a limb.

DECLARATION OF INTEREST

The authors have received no financial support for the material presented in this study outside of the scope of standard patient care reimbursement. This work was supported by the National Natural Science Foundation of China (NO. 81500596) awarded to Dr Wuquan Deng.

Injectable gentamicin-loaded thermo-responsive hyaluronic acid derivative prevents infection in a rabbit model

Despite the use of systemic antibiotic prophylaxis, the surgical fixation of open fractures with osteosynthesis implants is associated with high infection rates. Antibiotic-loaded biomaterials (ALBs) are increasingly used in implant surgeries across medical specialties to deliver high concentrations of antibiotics to the surgical site and reduce the risk of implant-associated infection. ALBs which are either less or not restricted in terms of spatial distribution and which may be applied throughout complex wounds could offer improved protection against infection in open fracture care. A thermo-responsive hyaluronic acid derivative (hyaluronic acid-poly(N-isopropylacrylamide) (HApN)) was prepared by a direct amidation reaction between the tetrabutyl ammonium (TBA) salt of hyaluronic acid and amine-terminated poly(N-isopropylacrylamide) (pN). The degree of grafting, and gelation properties of this gel were characterized, and the composition was loaded with gentamicin. The rheological- and release properties of this gentamicin-loaded HApN composition were tested in vitro and its efficacy in preventing infection was tested in a rabbit model of osteosynthesis contaminated with Staphylococcus aureus. The gentamicin-loaded HApN composition was able to prevent bacterial colonization of the implant site as shown by quantitative bacteriology. This finding was supported by histopathological evaluation of the humeri samples where no bacteria were found in the stained sections. In conclusion, this gentamicin-loaded HApN hydrogel effectively prevents infection in a complex wound, simulating a contaminated fracture treated with plating osteosynthesis.

STATEMENT OF SIGNIFICANCE

Fracture fixation after trauma is associated with high infection rates. Antibiotic loaded biomaterials (ALBs) can provide high local concentrations without systemic side effects. However, the currently available ALBs have limited accessibility to contaminated tissues in open fractures because of predetermined shape. Thus, a novel thermo-responsive hyaluronan based hydrogel with control over gelation temperature is reported. The efficacy of this gentamicin loaded hyaluronan derivative is demonstrated in an in vivo fracture model in the presence of fracture fixation hardware. The bacterial burden is cleared in all of the inoculated rabbits in the presence of the ALB. Thus, the proposed injectable thermo-responsive hyaluronan presents an effective ALB for the prevention of infection.

Advantages of Pure Platelet-Rich Plasma Compared with Leukocyte- and Platelet-Rich Plasma in Treating Rabbit Knee Osteoarthritis

Background

Concentrated leukocytes in leukocyte- and platelet-rich plasma (L-PRP) may deliver increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage. However, to date no relevant studies have substantiated that in vivo.

Material/Methods

Autologous L-PRP and pure platelet-rich plasma (P-PRP) were prepared, measured for componential composition, and injected intra-articularly after 4, 5, and 6 weeks post-anterior cruciate ligament transection. Caffeic acid phenethyl ester (CAPE) was injected intraperitoneally to inhibit NF-κB activation. All rabbits were sacrificed after 8 weeks postoperative. Enzyme-linked immunosorbent assays were performed to determine interleukin 1β (IL-1β) and prostaglandin E2 (PGE2) concentrations in the synovial fluid, Indian ink staining was performed for gross morphological assessment, and hematoxylin and eosin staining and toluidine blue staining were performed for histological assessment.

Results

Compared with L-PRP, P-PRP injections achieved better outcomes regarding the prevention of cartilage destruction, preservation of cartilaginous matrix, and reduction of IL-1β and PGE2 concentrations. CAPE injections reversed the increased IL-1β and PGE2 concentrations in the synovial fluid after L-PRP injections and improved the outcome of L-PRP injections to a level similar to P-PRP injections, while they had no influence on the therapeutic efficacy of P-PRP injections.

Conclusions

Concentrated leukocytes in L-PRP may release increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage, and finally, result in a inferior efficacy of L-PRP to P-PRP for the treatment of osteoarthritis.

Antimicrobial properties of platelet-rich preparations. A systematic review of the current pre-clinical evidence

In recent years autologous platelet concentrates (APCs) have become popular in several medicine fields, representing a valuable adjunct to regenerative surgical procedures. Beneficial effects in the control of postsurgical discomfort and infection have also been frequently reported, suggesting that APC may possess anti-inflammatory and antimicrobial properties. The aim of the present review was to summarize the current evidence regarding the antimicrobial effects of platelet concentrates, investigated by in vitro and animal studies. This review was conducted following a systematic approach. An electronic search was performed on MEDLINE, EMBASE and Scopus databases using appropriate search terms, without language or time restrictions. Preclinical studies assessing the antimicrobial activity of APC were included and divided according to the experimental design. Twenty in vitro studies and four animal studies, investigating APC effects on a broad range of microorganisms, were included. In in vitro studies APC reduced the growth of microorganisms during the first hours of incubation, while they could not completely break down the microbial load. In fact, over time a recovery of bacterial growth was always observed, suggesting that APCs display a bacteriostatic rather than a microbicidal activity. All animal studies showed that APC administered by local injections were able to reduce the infection caused by different microorganisms, although to a lesser extent compared to antibiotics. In conclusion, although the exact action mechanisms of interaction with microbial pathogens need further investigation, platelet concentrates proved to have antimicrobial properties, and therefore could represent a useful natural substance for controlling postoperative infections at surgical sites.

Modelling for conflict: the legacy of ballistic research and current extremity in vivo modelling

Extremity ballistic injury is unique and the literature intended to guide its management is commonly misinterpreted. In order to care for those injured in conflict and conduct appropriate research, clinicians must be able to identify key in vivo studies, understand their weaknesses and desist the propagation of miscited and misunderstood ballistic dogma. This review provides the only inclusive critical overview of key studies of relevance to military extremity injury. In addition, the non-ballistic studies of limb injury, stabilisation and contamination that will form the basis from which future small animal extremity studies are constructed are presented. With an awareness of the legacy of military wound models and an insight into available generic models of extremity injury and contamination, research teams are well placed to optimise future military extremity injury management.

Augmenting tendon and ligament repair with platelet-rich plasma (PRP)

Tendon and ligament injuries (TLI) commonly occur in athletes and non-athletes alike, and remarkably debilitate patients' athletic and personal abilities. Current clinical treatments, such as reconstruction surgeries, do not adequately heal these injuries and often result in the formation of scar tissue that is prone to re-injury. Platelet-rich plasma (PRP) is a widely used alternative option that is also safe because of its autologous nature. PRP contains a number of growth factors that are responsible for its potential to heal TLIs effectively. In this review, we provide a comprehensive report on PRP. While basic science studies in general indicate the potential of PRP to treat TLIs effectively, a review of existing literature on the clinical use of PRP for the treatment of TLIs indicates a lack of consensus due to varied treatment outcomes. This suggests that current PRP treatment protocols for TLIs may not be optimal, and that not all TLIs may be effectively treated with PRP. Certainly, additional basic science studies are needed to develop optimal treatment protocols and determine those TLI conditions that can be treated effectively.

Efficacy of leukocyte- and platelet-rich plasma gel (L-PRP gel) in treating osteomyelitis in a rabbit model

Leukocyte- and platelet-rich plasma gel (L-PRP gel), a new autologous product which was previously utilized in several surgical procedures to enhance tissue healing, is now increasingly used as a promising treatment method for infections. In this study, we investigated the antibacterial property of L-PRP gel against Methicillin-resistive Staphylococcus aureus (MRSA, ATCC 43300) in a rabbit model of osteomyelitis. Tibial osteomyelitis was induced in 40 New Zealand white rabbits using the MRSA strain. Three weeks after induction, the rabbits with tibial osteomyelitis were randomly divided into four groups: Control group (no treatment); Van group (debridement and parenteral treatment with vancomycin alone); L-PRP gel + Van group (debridement and local L-PRP gel injection, plus parenteral treatment with vancomycin); L-PRP gel group (debridement and local L-PRP gel injection). All rabbits were sacrificed 6 weeks after debridement. The antibacterial efficacy was evaluated by radiological, microbiological, and histological examinations. Newly formed bone was also quantified. The best therapeutic efficacy, including infection elimination and bone defect repair, was observed in the L-PRP gel + Van group. Although not comparable to vancomycin, L-PRP gel also exibited antimicrobial efficacy in vivo. We believe that a combination of L-PRP gel and antibiotics could be a favorable alternative for the treatment of osteomyelitis.

Comparative evaluation of MSCs from bone marrow and adipose tissue seeded in PRP-derived scaffold for cartilage regeneration

The aims of this study were to (1) determine whether platelet-rich plasma (PRP) could be prepared as a bioactive scaffold capable of endogenous growth factor release for cartilage repair; (2) compare the chondrogenic differentiation ability of mesenchymal stem cells (MSCs) from bone marrow (BMSC) and from adipose (ADSC) seeded within the PRP scaffold; and (3) test the efficacy of ADSC-PRP construct in cartilage regeneration in vivo. In vitro evaluation showed that a 3-dimensional scaffold with a mesh-like microstructure was formed from PRP, with the capability of endogenous growth factor release and ready cell incorporation. Upon seeding in the PRP scaffold, BMSC showed higher proliferation rate, and higher expression of cartilage-specific genes and proteins than ADSC. In an osteochondral defect model in rabbits, implanted BMSC seeded within PRP scaffold also exhibited better gross appearance and histological and immunohistochemical characteristics, higher cartilage-specific gene and protein expression as well as subchondral bone regeneration. ADSC seeded constructs developed into functional chondrocytes secreting cartilaginous matrix in rabbits at 9 weeks post-implantation. Our findings suggest that PRP is a candidate bioactive scaffold capable of releasing endogenous growth factors and that BMSC and ADSC seeded within the PRP scaffold differentiate into chondrocytes and may be suitable for cell-based cartilage repair.

Chronic calcaneal osteomyelitis associated with soft-tissue defect could be successfully treated with platelet-rich plasma: a case report

Chronic osteomyelitis associated with soft-tissue defect following surgical management is a severe complication for orthopaedic surgeons. Traditionally, the treatment protocol for the notorious complication involved thorough debridement, bone grafting, long-term antibiotic use and flap surgery. Alternatively, platelet-rich plasma (PRP), a high concentration of platelets collected via centrifugation, has been successfully used as an adjuvant treatment for bone and soft-tissue infection in medical practices. PRP has numerous significant advantages, including stypsis, inflammation remission and reducing the amount of infected fluid. It increases bone and soft-tissue healing and allows fewer opportunities for transplant rejection. Through many years of studies showing the advantages of PRP, it has become preferred organic product for the clinical treatment of infections, especially for chronic osteomyelitis associated with soft-tissue defect. To promote the clinical use of this simple and efficacious technique in trauma, we report the case of a patient with chronic calcaneal osteomyelitis associated with soft-tissue defect that healed uneventfully with PRP.