Platelet lysate promotes re-epithelialization of persistent epithelial defects: a pilot study

Three-dimensional cultures of gingival fibroblasts on fibrin-based scaffolds for gingival augmentation: A proof-of-concept study

OBJECTIVE

Gingival tissue regeneration is associated with several challenges. Tissue engineering regenerates the different components of the tissues, providing three major elements: living cells, appropriate scaffolds, and tissue-inducing substances. This study aimed to regenerate the gingival connective tissue in vitro, using human gingival fibroblasts cultured in three-dimensional fibrin gel scaffolds.

DESIGN

Human gingival fibroblasts were seeded in a novel three-dimensional fibrin gel scaffold and maintained in two media types: platelet lysate media (control) and collagen-stimulating media (test). Cellular viability and proliferation were assessed, and the production of collagen and other extracellular matrix components in these constructs was investigated and compared.

RESULTS

Human gingival fibroblasts cultured in three-dimensional cultures were metabolically active and proliferated in both media. Furthermore, histologic sections, scanning electron microscopy, and quantitative polymerase chain reaction confirmed the production of higher levels of collagen and other extracellular matrix fibers in three-dimensional constructs cultured in collagen-stimulating media.

CONCLUSIONS

Culturing human gingival fibroblasts in a novel three-dimensional fibrin gel scaffold containing collagen-stimulating media resulted in a tissue-equivalent construct that mimics human gingival connective tissue. The impact of these results should be considered for further investigations, which may help to develop a compatible scaffold for gingival soft tissue regeneration and treatment of mucogingival deformities.

Cytokines in equine platelet lysate and related blood products

In equine medicine, the use of regenerative therapeutics has gained growing attention, but is still a new and complex field with room for improvement. Platelet lysate (PL) can be used as therapeutic agent but is also a promising supplement for the culture of multipotent mesenchymal stromal cells. To enable a targeted use of PL both in clinic and laboratory, it is crucial to learn more details on its effective ingredients. While so far, mainly growth factor components have been analyzed in platelet-based products such as PL, the current study focuses on the content of cytokines in serum, plasma, platelet concentrate and PL. Blood was harvested from 20 clinically healthy horses and subjected to blood count and chemistry analysis, as well as to further processing to PL. Plasma and platelet concentrate were produced by a buffy-coat-based method and PL was produced from the concentrate by freeze-thawing. Samples from each horse were analyzed regarding interleukin (IL)-1β, −4, −6 and −10, interferon-γ and tumor necrosis factor-α concentrations using sandwich ELISAs. Cytokine concentrations in serum, plasma, concentrate and PL were similar and correlated significantly. However, there was a large inter-individual variability in cytokine concentrations between the different donor horses. The samples from some donor animals had overall very high cytokine concentrations, while samples from other donors had no measurable cytokine ingredient. This pattern was observed for all cytokines. There was a noticeable link between high cytokine concentrations in the blood products and abnormal findings in blood chemistry. Cytokine concentrations in samples from horses with abnormal findings were significantly higher than in samples from the remaining horses. The interindividual differences in cytokine concentrations could be highly relevant when using PL for therapy and cell culture, as the mode of action of the PL is likely changed depending on the presence of pro- and anti-inflammatory cytokines. Blood chemistry might be useful to predict cytokine concentrations in blood products.

Proliferation and Differentiation of Intestinal Caco-2 Cells Are Maintained in Culture with Human Platelet Lysate Instead of Fetal Calf Serum

Cell lines are widely used as in vitro model systems and substitute for animal experiments. The frequently used Caco-2 cell line is considered to reflect characteristics of differentiated intestinal epithelium. However, the need to culture the cells with fetal calf serum (FCS) induces a high variability, risk of contamination and is ethically disputed. We tested the culture of Caco-2 cells with human platelet lysate (PL) instead of FCS. We compared cell viability and differentiation by measuring ATP levels, gene and protein expression of specific markers in total cell extracts, brush border membrane vesicles (BBM) and lipid rafts (LR). Cell viability was slightly enhanced in cells grown with PL compared to FCS. The cells differentiated to an intestinal phenotype like the cells cultured in FCS, as indicated by the similar gene expression levels of hexose and protein transport proteins and the structural protein VILLIN. BBM showed a comparable distribution of the intestinal hydrolases, indicating a maintained cell membrane polarity. The distribution of the marker protein FLOTILLIN-2 in LR was also similar. We conclude that PL is an exquisite and suitable replacement for FCS in the culture of Caco-2 cells that can eliminate many disadvantages incurred due to the use of FCS.

The platelet-rich plasma lysate use in the treatment of persistent epithelial defects after keratoplasty

AIM:to evaluate the effectiveness of the platelet-rich plasma lysate (PRP lysate) use in the treatment of persistent epithelial defects (PED) after keratoplasty. MATERIALS AND METHODS:In the study, 60 patients with PED after keratoplasty were included. The 1st group (24 cases)included patients after keratoplasty with low risk of rejection, and the 2nd group 36 cases after keratoplasty with highrisk of rejection. Each group was divided into two subgroupscontrol subgroups 1a (cases 10) and 2a (cases 16), where patients received only standard postoperative therapy, and the main subgroups 1b (cases 14) and 2b (cases 20), in which PRP lysate was prescribed against the background of standard therapy, starting from the Day 15 post-op. As the criterion for effective treatment, complete persistent epithelialization after keratoplasty was considered. RESULTS:The effectiveness of the use of PRP lysate in the subgroup 1b was 85.7%, while complete epithelialization in the control subgroup 1a was recorded in 70%; in the subgroup 2b, complete epithelialization was observed in 55%, in the control subgroup 2ain 43.75%. CONCLUSION:The use of PRP lysate in the treatment of PED after corneal transplantation as an adjuvant therapy is effective and safe in both high and low risk keratoplasty. In the examined category of patients, treatment with blood derivatives increases the frequency and rate of complete epithelialization.

[Modern biotechnological treatment methods of persistent corneal epithelial defects]

The article reviews modern methods of treatment of persistent corneal epithelial defects and considers the factors involved in the development of this pathology, including the limbal stem cell deficiency, which is likely to play the main role. The most promising treatment methods are described, particularly the use of blood derivatives and cell therapy.

Platelet lysate promotes the healing of long-standing diabetic foot ulcers: A report of two cases and in vitro study

Long-standing foot ulcers present a great challenge in diabetes care. Platelet products have been suggested as a possible therapeutic option. However, nor the effect of an injectable form of platelet lysate on the healing of ulcers nor that on primary cells of the epidermis have been studied. In the current study, we present two cases of an ongoing clinical trial showing the positive effect of autologous platelet lysate injected perilesional. Both clinical cases treated with injections of hPL showed complete healing of previously un-healed within 8 weeks of treatment. Further, we describe the in vitro effect of human platelet lysate (hPL) on primary human epidermal keratinocytes (HEK) in terms of chemotaxis, migration and proliferation. In vitro, HEK showed enhanced chemotaxis towards the hPL compared to keratinocyte-defined media (p < 0.0001). Their migration was also stimulated especially at hPL concentration of 10%V/V (p < 0.0001). In contrast, hPL significantly inhibited HEK proliferation measured through MTT assay (p < 0.0001). In conclusion, the findings presented here provide preliminary evidence of an explanatory mechanism for the effect of hPL on primary keratinocytes and therefore of their potential use in a clinical setting. hPL promotes keratinocyte migration and therefore closure of foot ulcers.

hPL promotes osteogenic differentiation of stem cells in 3D scaffolds

Human platelet lysate (hPL) has been considered as the preferred supplement for the xeno-free stem cell culture for many years. However, the biological effect of hPL on the proliferation and differentiation of dental stem cells combined with the use of medical grade synthetic biomaterial is still under investigation. Thus, the optimal scaffold composition, cell type and specific growth conditions, yet need to be formulated. In this study, we aimed to investigate the regenerative potential of dental stem cells seeded on synthetic scaffolds and maintained in osteogenic media supplemented with either hPL or xeno-derived fetal bovine serum (FBS). Two types of dental stem cells were isolated from human impacted third molars and intact teeth; stem cells of apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs). Cells were expanded in cell culture media supplemented with either hPL or FBS. Consequently, proliferative capacity, immunophenotypic characteristics and multilineage differentiation potential of the derived cells were evaluated on monolayer culture (2D) and on synthetic scaffolds fabricated from poly ’lactic-co-glycolic’ acid (PLGA) (3D). The functionality of the induced cells was examined by measuring the concentration of osteogenic markers ALP, OCN and OPN at different time points. Our results indicate that the isolated dental stem cells showed similar mesenchymal characteristics when cultured on hPL or FBS-containing culture media. Scanning electron microscopy (SEM) and H&E staining revealed the proper adherence of the derived cells on the 3D scaffold cultures. Moreover, the increase in the concentration of osteogenic markers proved that hPL was able to produce functional osteoblasts in both culture conditions (2D and 3D), in a way similar to FBS culture. These results reveal that hPL provides a suitable substitute to the animal-derived serum, for the growth and functionality of both SCAP and PDLSCs. Thus the use of hPL, in combination with PLGA scaffolds, can be useful in future clinical trials for dental regeneration.

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 β, 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.