Effect of autologous PRP on wound healing in dental regenerative surgeries and its correlation with PDGF levels

Combination of PDGF-BB and adipose-derived stem cells accelerated wound healing through modulating PTEN/AKT pathway

Adipose-derived stem cells (ADSCs) have been widely proven to facilitate wound healing. Our study aimed to estimate the influence of combined ADSCs and platelet-derived growth factor-BB (PDGF-BB) on wound healing. We utilized 4 healthy SD rats to isolate ADSCs. Platelet-rich plasma (PRP) was acquired utilizing a two-step centrifugation technology. The role of PRP, PDGF-BB, and PDGF-BB combined with a PI3k inhibitor LY294002 on the viability, migration, and PTEN/AKT pathway in ADSCs were examined utilizing CCK-8, Transwell, and western blot assays. Then, we constructed an open trauma model in SD rats. Effects of ADSCs treated with PDGF-BB on pathological changes, CD31, and PTEN/AKT pathway of wound closure were assessed by hematoxylin & eosin (H&E) staining, Masson staining, immunohistochemical, and western blot assays, respectively. PRP and PDGF-BB intensified the viability and migration of ADSCs by modulating the PTEN/AKT pathway. Interestingly, LY294002 reversed the role of PDGF-BB on ADSCs. In vivo experiments, combined intervention with ADSCs plus PDGF-BB/PRP facilitated wound closure and ameliorated histological injury. Moreover, combined intervention with ADSCs and PDGF-BB attenuated the PTEN level and elevated the CD31 level as well as the ratio of p-AKT/AKT in the skin tissues. A combination of ADSCs and PDGF-BB facilitated wound healing might associate with the regulation of the PTEN/AKT pathway.

Effect of Mechanical Stimulation Combined With Platelet-Rich Plasma on Healing of the Rotator Cuff in a Murine Model

BACKGROUND

Mechanical stimulation and platelet-rich plasma (PRP) have been shown to be beneficial for healing of the bone-tendon interface (BTI), but few studies have explored the efficacy of a combination of these applications. We investigated the effect of mechanical stimulation combined with PRP on rotator cuff repair in mice.

HYPOTHESIS

Mechanical stimulation combined with PRP can enhance BTI healing in a murine model of rotator cuff repair.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 160 C57BL/6 mice were used. Overall, 40 mice were used to prepare PRP, while 120 mice underwent acute supraspinatus tendon (SST) repair. The animals were randomly assigned to 4 groups: control group, mechanical stimulation group, PRP group, and mechanical stimulation combined with PRP group (combination group). At 4 and 8 weeks postoperatively, animals were sacrificed, the eyeballs were removed to collect blood, and the SST-humeral complexes were collected. Histological, biomechanical, immunological, and bone morphometric tests were performed.

RESULTS

Histologically, at 4 and 8 weeks after surgery, the area of the fibrocartilage layer at the BTI in the combination group was larger than in the other groups. The content and distribution of proteoglycans in this layer in the combination group were significantly greater than in the other groups. At 8 weeks postoperatively, trabecular number, and trabecular bone thickness of the subchondral bone area of interest at the BTI of the combination group were greater than those of the other groups, bone volume fraction of the combination group was greater than the control group. On biomechanical testing at 4 and 8 weeks after surgery, the failure load and ultimate strength of the SST-humeral complex in the combination group were higher than in the other groups. Enzyme-linked immunosorbent assay results showed that, at 4 weeks postoperatively, the serum concentrations of transforming growth factor beta 1 and platelet-derived growth factor (PDGF) in the combination group were significantly higher than in the other groups; at 8 weeks, the PDGF-AB concentration in the combination group was higher than in the control and mechanical stimulation groups.

CONCLUSION

Mechanical stimulation combined with PRP can effectively promote the early stage of healing after a rotator cuff injury.

CLINICAL RELEVANCE

These findings imply that mechanical stimulation combined with PRP can serve as a potential therapeutic strategy for rotator cuff healing.

Intraovarian injection of platelet-rich plasma in assisted reproduction: too much too soon?

The prospect of ovarian rejuvenation offers the tantalising prospect of treating age-related declines in fertility or in pathological conditions such as premature ovarian failure. The concept of ovarian rejuvenation was invigorated by the indication of the existence of oogonial stem cells (OSCs), which have been shown experimentally to have the ability to differentiate into functional follicles and generate oocytes; however, their clinical potential remains unknown. Furthermore, there is now growing interest in performing ovarian rejuvenation in situ. One proposed approach involves injecting the ovary with platelet rich plasma (PRP).

PRP is a component of blood that remains after the in vitro removal of red and white blood cells. It contains blood platelets, tiny anucleate cells of the blood, which are responsible for forming athrombus to prevent bleeding. In addition, PRP contains an array of cytokines and growth factors, as well as a number of small molecules.The utility ofPRP has been investigatedin a range of regenerative medicine approaches and has been shown to induce differentiation of a range of cell types, presumably through the action of cytokines.

A handful ofcasereports have described the use of PRP injections into the ovaryin the human, and while these clinical data report promising results, knowledge on the mechanisms and safety of PRP injections into the ovary remain limited.In this article, we summarise some of the physiological detail of platelets and PRP, before reviewing the existing emerging literature in this area. We then propose potential mechanisms by which PRP may be eliciting any effects before reflecting on some considerations for future studies in the area. Importantly, on the basis of our existing knowledge, we suggest that immediate use of PRP in clinical applications is perhaps premature and further fundamental and clinical research on the nature of ovarian insufficiency, as well as the mechanism by which PRP may act on the ovary, is needed to fully understand this promising development.

Application of Concentrated Growth Factors Membrane for Human Umbilical Cord Wharton’s Jelly Mesenchymal Stem Cell Differentiation towards Keratinocytes

Concentrated growth factors are extracted from platelet-rich plasma obtained from healthy adult veins by physical gradient centrifugation, and the activated platelets release various growth factors and cytokines, which can be further converted into concentrated growth factors liquid or gel preparations by different centrifuge tubes. These preparations are widely used in clinical treatments in various fields, such as dentistry, dermatology and surgery. In this article, concentrated growth factors gel and platelet-poor plasma gel obtained from six healthy adults were pressed into a concentrated growth factors membrane and platelet-poor plasma membrane. We examined whether the 3D fibrin mesh and the various concentrated growth factors within the concentrated growth factors membrane could be used as a bioscaffold for the human Wharton’s jelly umbilical cord stem cell line or the HaCaT cell line to attach, proliferate and form epidermal-like tissue. We also aimed to implant umbilical cord stem cells on the concentrated growth factors membrane or platelet-poor plasma membrane, and further compare the characteristics of similar tissues after 4 weeks in in vitro culture. The results showed that human Wharton’s jelly umbilical cord mesenchymal stem cells, implanted on the upper surface of the concentrated growth factors membrane, showed subsequent cell attachment and proliferation. After 4 weeks of ex vivo tissue culture, a multi-layer epidermal-like tissue formed on the upper surface of the membrane containing concentrated growth factors. This tissue had a minimum thickness of 89.91 µm to a maximum of 204.19 µm, mean ± SD = 144.36 µm ± 43.14 µm. Sections of these multi-layer epidermal-like tissues were used for immunohistochemical staining. We found that 79.8% ± 7.2% of the cells expressed the pancytokeratin marker, 29.5% ± 9.4% of the cells expressed the P63 marker, and 71.7% ± 3.9% of the cells expressed the vimentin marker. After the same 4 weeks in the in vitro culture, the HaCaT cells could attach to the concentrated growth factors membrane and proliferate to form a multi-layer tissue, The tissue had a minimum thickness of 63.17 µm to a maximum of 100.26 µm, mean ± SD = 74.05 µm ± 13.44 µm. We found that 88.1% ± 4.9% of the cells expressed the pancytokeratin marker, 63.6% ± 11.4% of the cells expressed the P63 marker, and 79% ± 9.9% of the cells expressed the vimentin marker. Also, after 4 weeks in the in vitro culture, it showed that umbilical cord stem cells could attach to the platelet-poor plasma membrane, proliferate and distribute in the whole-tissue sections. We found that 9.7% ± 2.4% of the cells expressed the pancytokeratin marker, 7.45% ± 1.9% of the cells expressed the P63 maker, and 95.9% ± 3.7% of the cells expressed the vimentin marker. In terms of the percentage of umbilical cord stem cells expressing pancytokeratin, P63, or vimentin cell markers, there was a significant difference between cultivating in the concentrated growth factors membrane scaffold and the platelet-poor plasma membrane scaffolds. In terms of the percentage of umbilical cord stem cells or HaCaT cells (cultivating in the concentrated growth factors membrane) expressing pancytokeratin, P63, or vimentin cell markers, there was no significant difference. These results suggested that umbilical cord Wharton’s jelly mesenchymal stem cells can use the concentrated growth factors membrane (composed of 3D fibrin mesh, and various growth factors and cytokines) as an effective and self-contained bioscaffold to differentiate towards keratinocytes-like cells. In the future, donors’ own concentrated growth factors membrane can be applied as an auxiliary tool for autologous tissue regeneration.

The biological processes during wound healing

Numerous individuals suffer from impaired wound healing, such as chronic ulcers, severe burns and immune disorders, resulting in both public health and economic burdens. Skin is the first line of defense and the largest organ of the human body, however, an incomplete understanding of underlying cellular and molecular mechanisms of dermal repair leads to a lack of effective therapy for healing impaired wounds. There are strong clinical and social needs for improved therapeutic approaches to enhance endogenous tissue repair and regenerative capacity. The purpose of this review is to illuminate the cellular and molecular aspects of the healing process and highlight potential therapeutic strategies to accelerate translational research and the development of clinical therapies in dermal wounds.

Effects and mechanism of platelet-rich plasma on military drill injury: a review

Military drill injury is a significant part of military medical research. The increase of training intensity and changes in training methods lead to differences in injury types. The ideal therapeutic modality should allow rapid healing at a reasonable cost and minimize impact on patients' life. Platelet -rich plasma (PRP), a platelet concentrate, is rich in a variety of growth factors and widely used clinically as a minimally invasive treatment. It plays an important role in injury repair and rehabilitation. In this article, we review the therapeutic role of PRP in military drill injury and its possible underlying mechanisms, with a focus on plantar fasciitis, stress fractures and other common injuries, in order to provide basic support for military reserve.