Fibrin-Plasma Rich in Growth Factors Membrane for the Treatment of a Rabbit Alkali-Burn Lesion

Improving the mechanical and biological functions of cell sheet constructs: The interplay of human-derived periodontal ligament stem cells, endothelial cells and plasma rich in growth factors

OBJECTIVE

The aim of this study was to produce and characterize triple-layered cell sheet constructs with varying cell compositions combined or not with the fibrin membrane scaffold obtained by the technology of Plasma Rich in Growth Factors (mPRGF).

MATERIALS AND METHODS

Human primary cultures of periodontal ligament stem cells (hPDLSCs) were isolated, and their stemness nature was evaluated. Three types of triple-layered composite constructs were generated, composed solely of hPDLSCs or combined with human umbilical vein endothelial cells (HUVECs), either as a sandwiched endothelial layer or as coculture sheets of both cell phenotypes. These three triple-layered constructs were also manufactured using mPRGF as cell sheets' support. Necrosis, glucose consumption, secretion of extracellular matrix proteins and synthesis of proangiogenic factors were determined. Histological evaluations and proteomic analyses were also performed.

RESULTS

The inclusion of HUVECs did not clearly improve the properties of the multilayered constructs and yet hindered their optimal conformation. The presence of mPRGF prevented the shrinkage of cell sheets, stimulated the metabolic activity and increased the matrix synthesis. At the proteome level, mPRGF conferred a dramatic advantage to the hPDLSC constructs in their ability to provide a suitable environment for tissue regeneration by inducing the expression of proteins necessary for bone morphogenesis and cellular proliferation.

CONCLUSIONS

hPDLSCs' triple-layer construct onto mPRGF emerges as the optimal structure for its use in regenerative therapeutics.

CLINICAL RELEVANCE

These results suggest the suitability of mPRGF as a promising tool to support cell sheet formation by improving their handling and biological functions.

Long-Term Comprehensive Management of Bilateral Limbal Stem Cell Deficiency Secondary to Severe Chemical Burn: 10 Years of Follow-Up

PURPOSE

To describe the long-term management of bilateral limbal stem cell deficiency secondary to a severe chemical burn.

METHODS

Descriptive case report.

IMPORTANCE

This case highlights the importance of early intervention in ocular chemical burns for the preservation of tissue integrity and avoidance of perforation. We also review the use of proper ocular surface reconstructive techniques to restore the function of the limbal area, as well as the immunomodulatory strategies and follow-up needed for these interventions.

Mini Cleanroom for the Manufacture of Advanced Therapy Medicinal Products (ATMP): Bioengineered Corneal Epithelium

Among several requirements for the manufacture of Advanced Therapy Medicinal Products (ATMP) are: following the guidelines of a pharmaceutical quality system, complying with Good Manufacturing Practice (GMP) and access to a cleanroom fulfilling strict environmental conditions (Class A work area and Class B environment). This makes ATMP expensive. Moreover, the production of many of these therapeutic products may also be unprofitable, as in most cases their use is limited to a few patients and to a single batch per manufacturing unit. To reduce costs, ATMP may be produced in a scaled-down system isolated from the external environment (isolator), allowing for placement of this facility in a Class D environment, which is much more permissive and less costly. In this work, we confirm that it is possible to manufacture bioengineered corneal epithelium inside an isolator while fulfilling all the safety assurance standards at an affordable cost for patients. This small-scale ultra-clean working environment complies with GMP guidelines and could be a solution for the high costs associated with conventional cleanroom ATMP production.