Novel therapeutic approaches in utilizing platelet lysate in regenerative medicine: Are we ready for clinical use?

Hemoderivative materials are used to treat different diseases. These derivatives include platelet-rich plasma, serum, platelet gel, and platelet lysate (PL). Among them, PL contains more growth factors than the others and its production is inexpensive and easy. PL is one of the proper sources of platelet release factors. It is used in cells growth and proliferation and is a good alternative to fetal bovine serum. In recent years, the clinical use of PL has gained more appeal by scientists. PL is a solution saturated by growth factors, proteins, cytokines, and chemokines and is administered to treat different diseases such as wound healing, bone regeneration, alopecia, oral mucositis, radicular pain, osteoarthritis, and ocular diseases. In addition, it can be used in cell culture for cell therapy and tissue transplantation purposes. Platelet-derived growth factor, fibroblast growth factor, insulin-like growth factor, transforming growth factor ß, and vascular endothelial growth factor are key PL growth factors playing a major role in cell proliferation, wound healing, and angiogenesis. In this paper, we scrutinized recent advances in using PL and PL-derived growth factors to treat diseases and in regenerative medicine, and the ability to replace PL with other hemoderivative materials.

Effect of low-intensity pulsed ultrasound on fracture callus mineral density and flexural strength in rabbit tibial fresh fracture.

BACKGROUND: Low-intensity ultrasound is a biophysical intervention on a fracture repair process. However, the effect of low-intensity ultrasound therapy on fracture healing is controversial. The aim of the present study was to evaluate the effect of low-intensity pulsed ultrasound (LIPUS) therapy on the fracture healing process, including mineral density and strength of callus using a rabbit model. METHODS: A total of 30 rabbits underwent unilateral, transverse, and mid-tibia open osteotomies that were stabilized with external fixators. Then, the animals were divided into two study groups composed of 15 rabbits each: the case group (US), which were exposed to low-intensity pulsed ultrasound with 30 mW/cm(2) intensity and 1.5 MHz sine waves; and the control group (C), which underwent sham ultrasound treatment. Callus development and mineral density were evaluated using multidetector computed tomography at 2, 5, and 8 weeks, after which the animals were killed. Three-point bending tests of both healed and intact bones were assessed and compared. RESULTS: The results demonstrated that the callus mineral density in the US group was higher than in the C group (1202.20 +/- 81.30 vs. 940.66 +/- 151.58 HU; P = 0.001) at the end of the 8th week. The mean recorded three-point bending test score of healed bones in the US group was not significantly different from that of the C group (359.35 +/- 173.39 vs. 311.02 +/- 80.58 N; P = 0.114). CONCLUSIONS: The present study showed that low-intensity pulsed ultrasound enhanced callus mineral density with an insignificant increase in the strength of the fractured bone.