The effect of intraarticular serum rich in growth factors (SRGF) on knee osteoarthritis in the rat model

Platelet-rich plasma injections induce disease-modifying effects in the treatment of osteoarthritis in animal models

PURPOSE

The mechanisms of action and disease-modifying potential of platelet-rich plasma (PRP) injection for osteoarthritis (OA) treatment are still not fully established. The aim of this systematic review of preclinical evidence was to determine if PRP injections can induce disease-modifying effects in OA joints.

METHODS

A systematic review was performed on animal studies evaluating intra-articular PRP injections as treatment for OA joints. A synthesis of the results was performed investigating the disease-modifying effects of PRP by evaluating studies that compared PRP with OA controls or other injectable products, different PRP formulations or injection intervals, and the combination of PRP with other products. The risk of bias was assessed according to the SYRCLE's tool.

RESULTS

Forty-four articles were included, for a total of 1251 animals. The publication trend remarkably increased over time. PRP injections showed clinical effects in 80% and disease-modifying effects in 68% of the studies, attenuating cartilage damage progression and reducing synovial inflammation, coupled with changes in biomarker levels. Evidence is limited on the best PRP formulation, injection intervals, and synergistic effect with other injectables. The risk of bias was low in 40%, unclear in 56%, and high in 4% of items.

CONCLUSION

Intra-articular PRP injections showed disease-modifying effects in most studies, both at the cartilage and synovial level. These findings in animal OA models can play a crucial role in understanding mechanism of action and structural effects of this biological approach. Nevertheless, the overall low quality of the published studies warrants further preclinical studies to confirm the positive findings, as well as high-level human trials to demonstrate if these results translate into disease-modifying effects when PRP is used in the clinical practice to treat OA.

LEVEL OF EVIDENCE

Level II.

Topical effect of allogenous serum rich in growth factors (SRGF) on diabetic skin wound in rat

Diabetic foot ulcer is a major complication of diabetes mellitus with negative effects on the life quality. Management of diabetic foot ulcers is a big challenge with poor and low sufficient outcome management. Therefore, achievement to effective treatments may treat these ulcers. Nowdays, platelet products are used as an effective and safe agent for promotion of healing proposes in regenerative medicine. Serum rich in growth factors (SRGF) is a source of released growth factors from the platelets. In the present study, effect of allogenous SRGF was investigated on the streptozotocin (STZ)-induced diabetic wounds in rats. STZ (50 mg/kh, SC) caused significant increase in blood glucose and weight loss in rats. Full thickness cutaneous wounds (8 mm diameter) were created bilaterally on the dorsal of the diabetic rats. SRGF was injected at the edges of the wounds of one side only on the first day, and the contrary sides were considered as the control group. The percentage of wound contraction was demonstrared on day 3, 7, 11 after surgery. Tissue specimens were collected for microscopic study on days 7 and 14. Results showed a significant higher rate of wound contraction on days 5 and 7 in the treated group. Histopathologic findings displayed acceleration of re-epithelialization, increased angiogenesis and dense collagen fibers with better organization in the treated group. Current study suggests that SRGF was efficient because facilate wound healing and showed rapid re-epithelialization and increased angiogenesis.

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.

Intra-articular effects of combined xenogenous serum rich in growth factors (SRGF) and vitamin C on histopathology grading and staging of osteoarthritis in rat model

OBJECTIVE

Osteoarthritis (OA) is one of the most common degenerative diseases especially in the knee joint. The definitive method for the treatment of this disease is not known. In recent years, use of platelet-derived products has been considered as a new therapeutic approach because of its low cost, easy to use, and minimum side effects. Serum rich of growth factors (SRGF) is one of the biological compounds used to healing and regeneration. Its effects may improve in combination with antioxidants such as vitamin C. This vitamin increases the synthesis of proteoglycans by chondrocytes. The present study investigated effect of xenogenous SRGF in combination with vitamin C on the monosodium iodoacetate-induction osteoarthritis in rats.

METHODS

Animals were randomly categorized into three groups including OA, SRGF, and vitamin C+SRGF. Treatments were performed with 3 time intra-articular injection in weekly intervals. Knee samples were taken after two weeks of the last treatment for histopathologic investigations.

RESULTS

In the OA group, surface fibrillation and irregularity, multiple clefts, loss of chondrocytes, proteoglycan depletion with Toluidine blue staining were detected. In the treated group with SRGF/vitamin C, the severity of degenerative lesions was decreased. Chondrocytes had proliferated and matrix proteoglycan increased in compared to the SRGF and OA groups. Also, osteoarthritis stage was markedly reduced in this group rather than two other groups.

CONCLUSION

The results of this study show the synergic effect of vitamin C and growth factors on accelerating articular repair.