A side-effect induced by the combination of a demineralized freeze-dried bone allograft and leucocyte and platelet-rich plasma during treatment for large bone cysts: A 4-year follow-up clinical study

Plasma rich in growth factors (PRGF) and leukocyte-platelet rich fibrin (L-PRF): comparative release of growth factors and biological effect on osteoblasts

PURPOSE

To compare the release of platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF-I) and interleukin 1β (IL-1β) of plasma rich in growth factors (PRGF) and leucocyte platelet-rich fibrin (L-PRF) and to evaluate their biological implication in osteoblasts.

METHODS

Blood from 3 healthy volunteers was processed into PRGF, immediate L-PRF (L-PRF 0') and L-PRF 30 min after collection (L-PRF-30') and a control group. Growth factors release were analyzed at 7 times by ELISA. Cell proliferation, collagen-I synthesis and alkaline phosphatase activity were assessed in primary cultures of human osteoblasts.

RESULTS

A slower controlled release of IGF-I, VEGF and PDGF was observed in the PRGF group at day 14. A higher synthesis of type I collagen was also quantified in PRGF. L-PRF released significantly higher amounts of IL-1β, that was almost absent in the PRGF.

CONCLUSIONS

The addition of leukocytes dramatically increases the secretion of proinflammatory cytokines, which are likely to negatively influence the synthesis of type I collagen and alkaline phosphatase (ALP) by osteoblasts.

A Call for Standardization in Platelet-Rich Plasma Preparation Protocols and Composition Reporting: A Systematic Review of the Clinical Orthopaedic Literature

BACKGROUND

Platelet-rich plasma (PRP) is a blood-derived preparation whose use has grown exponentially in orthopaedic practice. However, there remains an unclear understanding of the biological properties and effects of PRP on musculoskeletal healing. Heterogeneous processing methods, unstandardized nomenclature, and ambiguous classifications make comparison among studies challenging. A comprehensive assessment of orthopaedic clinical PRP trials is key to unraveling the biological complexity of PRP, while improving standardized communication. Toward this goal, we performed a systematic review of the PRP preparation protocols and PRP composition utilized in clinical trials for the treatment of musculoskeletal diseases.

METHODS

A systematic review of the literature was performed from 2006 to 2016. Inclusion criteria were human clinical trials, English-language literature, and manuscripts that reported on the use of PRP in musculoskeletal/orthopaedic conditions. Basic-science articles, editorials, surveys, special topics, letters to the editor, personal correspondence, and nonorthopaedic applications (including cosmetic use or dental application studies) were excluded.

RESULTS

A total of 105 studies (in 104 articles) met the inclusion criteria for analysis. Of these studies, only 11 (10%) provided comprehensive reporting that included a clear description of the preparation protocol that could be used by subsequent investigators to repeat the method. Only 17 studies (16%) provided quantitative metrics on the composition of the final PRP product.

CONCLUSIONS

Reporting of PRP preparation protocols in clinical studies is highly inconsistent, and the majority of studies did not provide sufficient information to allow the protocol to be reproduced. Furthermore, the current reporting of PRP preparation and composition does not enable comparison of the PRP products being delivered to patients. A detailed, precise, and stepwise description of the PRP preparation protocol is required to allow comparison among studies and provide reproducibility.

Comparison of the effects of platelet-rich or growth factor-rich plasma on intestinal anastomosis healing in pigs

Background

The use of autologous platelet-rich plasma (PRP) and plasma rich in growth factors (PRGF) has been proposed for the treatment of several acute and chronic syndromes, such as corneal epithelial defects and dry eye syndrome, gum bleeding during oral surgery, and in orthopaedic surgery. We hypothesized that PRGF, rather than PRP, could be more effective because of its intrinsic characteristics in promoting the healing of intestinal anastomosis. The purpose of the present study was to evaluate and compare the effects of PRP and PRGF on various parameters of anastomotic healing in a swine model.

Methods

Eight female pigs were randomly assigned to two groups and subjected to hand sewn jeujuno-jejunal appositional extramucosal anastomoses. For each animal, a total of six anastomoses were performed: two were considered controls and received no treatment, while the remaining four anastomoses were treated with PRP or PRGF of which both were prepared at a platelet concentration that was respectively 3.4-fold and 2.81-fold higher than the original platelet count. In each animal, either PRP or PRGF was used as a treatment, to avoid interference among products. Animals were euthanized after 8 days and the anastomoses were evaluated and compared for the presence of adhesions, anastomotic leakage, bursting pressure, and histological appearance.

Results

The concentration of platelets in PRP was 3.41-fold higher (range, 3.20–4.24) that the concentration in whole blood, while the concentration in PRGF was 2.81-fold higher (range, 2.89–4.88).

The results obtained from the present study highlighted that there are no differences between anastomotic samples treated with either PRP or PRGF preparations, except for a significant increase in epithelization of the intestinal mucosa at the anastomotic site in the PRGF group.

Conclusions

Both PRP and PRGF suspensions should be considered a safe strategy and represent a relatively low-cost technology that is flexible enough to be applied in several therapeutic fields. No true benefit could be proven in our study compared to the no treatment following anastomoses formation, with the exception of enhanced epithelization of the mucosa in the PRGF group.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-017-1102-8) contains supplementary material, which is available to authorized users.

Benefit of Leukocyte- and Platelet-Rich Plasma in Operative Wound Closure in Oral and Maxillofacial Surgery

This article reports the influence of an autologous leukocyte- and platelet-rich plasma (L-PRP) injection as a minimally invasive method on supporting wound healing processes after a mandibular odontogenic cystectomy and double mandibular fracture fixation. 113 patients were enrolled into a control group (received no L-PRP injection) and 102 patients were enrolled into an L-PRP group with an oral mucosa incision. 18 patients after a double mandibular fracture were operated on using 2 external submandibular approaches receiving no fluids in the right site (a control group) and an L-PRP injection in the left incision (L-PRP group). Clinical observations showed that the oral mucosa healed faster in patients treated with L-PRP, in comparison to cases where inductive biomaterial was not added. Pain at the L-PRP injection site was relieved within few hours after an operation in patients with double mandibular fractures. However, there were no differences observed in the progression of the healing process. L-PRP possesses inductive properties that could stimulate healing processes and it seems to be one of the most promising methods in the future for the treatment of soft tissue defects.

Morphogen and proinflammatory cytokine release kinetics from PRGF-Endoret fibrin scaffolds: evaluation of the effect of leukocyte inclusion

The potential influence of leukocyte incorporation in the kinetic release of growth factors from platelet-rich plasma (PRP) may explain the conflicting efficiency of leukocyte platelet-rich plasma (L-PRP) scaffolds in tissue regeneration. To assess this hypothesis, leukocyte-free (PRGF-Endoret) and L-PRP fibrin scaffolds were prepared, and both morphogen and proinflammatory cytokine release kinetics were analyzed. Clots were incubated with culture medium to monitor protein release over 8 days. Furthermore, the different fibrin scaffolds were morphologically characterized. Results show that leukocyte-free fibrin matrices were homogenous while leukocyte-containing ones were heterogeneous, loose and cellular. Leukocyte incorporation produced a significant increase in the contents of proinflammatory cytokines interleukin (IL)-1β and IL-16 but not in the platelet-derived growth factors release (<1.5-fold). Surprisingly, the availability of vascular endothelial growth factor suffered an important decrease after 3 days of incubation in the case of L-PRP matrices. While the release of proinflammatory cytokines was almost absent or very low from PRGF-Endoret, the inclusion of leukocytes induced a major increase in these cytokines, which was characterized by the presence of a latent period. The PRGF-Endoret matrices were stable during the 8 days of incubation. The inclusion of leukocytes alters the growth factors release profile and also increased the dose of proinflammatory cytokines.

Treatment of unicameral bone cyst: systematic review and meta analysis

PURPOSE

Different treatment modalities have been utilized to treat unicameral bone cyst (UBC), but evidence has not been fully described to support one treatment over another and the optimal treatment is controversial. The aim of this quantitative systematic review was to assess the effectiveness of different UBC treatment modalities.

METHODS

We utilized Pubmed to isolate retrospective studies on patients with UBC who received any kind of treatment. The included studies needed to have a minimum sample size of 15 patients, and have provided data on radiographic healing outcome.

RESULTS

Sixty-two articles were selected for the meta-analysis from a total of 463 articles. The cumulative sample size was 3,211 patients with 3,217 UBC, and male to female ratio was 2.2:1. The summary or pool estimate of methylprednisolone acetate (MPA) injection resulted in a healing rate of (77.4 %) that was comparable to bone marrow injection (77.9 %). A higher healing rate was observed with MPA injection when inner wall disruption was performed. The pool estimate of bone marrow with demineralized bone matrix injection was high (98.7 %). UBC healing rate after surgical curettage was comparable whether autograft or allograft was utilized (90 %). UBC treatment with flexible intramedullary nails without curettage provided almost 100% healing rate, while continuous decompression with cannulated screws provided 89 % healing rate. Conservative treatment indicated a healing rate of 64.2, 95 % CI (26.7-101.8).

CONCLUSIONS

Active treatment for UBC provided variable healing rates and the outcomes were favorable relative to conservative treatment. Due to the heterogeneity of the studies and reporting bias, the interpretation of these findings should be handled with caution.

Release kinetics of platelet-derived and plasma-derived growth factors from autologous plasma rich in growth factors

Many studies have evaluated the biological effects of platelet rich plasma reporting the final outcomes on cell and tissues. However, few studies have dealt with the kinetics of growth factor delivery by plasma rich in growth factors. Venous blood was obtained from three healthy volunteers and processed with PRGF-Endoret technology to prepare autologous plasma rich in growth factors. The gel-like fibrin scaffolds were then incubated in triplicate, in a cell culture medium to monitor the release of PDGF-AB, VEGF, HGF and IGF-I during 8 days of incubation. A leukocyte-platelet rich plasma was prepared employing the same technology and the concentrations of growth factors and interleukin-1β were determined after 24h of incubation. After each period, the medium was collected, fibrin clot was destroyed and the supernatants were stored at -80°C until analysis. The growth factor delivery is diffusion controlled with a rapid initial release by 30% of the bioactive content after 1h of incubation and a steady state release when almost 70% of the growth factor content has been delivered. Autologous fibrin matrix retained almost 30% of the amount of the growth factors after 8 days of incubation. The addition of leukocytes to the formula of platelet rich plasma did not increase the concentration of the growth factors, while it drastically increased the presence of pro-inflammatory IL-1β. Further studies employing an in vitro inflammatory model would be interesting to study the difference in growth factors and pro-inflammatory cytokines between leukocyte-free and leukocyte-rich platelet rich plasma.