Isolation and differentiation potential of fibroblast-like stromal cells derived from human skin

Isolating human dermal fibroblasts using serial explant culture

Background

The purpose of this study was to introduce an applicable culture technique to isolate human dermal fibroblasts (HDFs); which could also contribute to research, clinical practices, as well as tissue engineering.

Methods

Samples from the human skin were dissected and cultured via serial explant technique. Subsequently, the isolated fibroblasts were assessed for their protein markers and genetic variations via immunofluorescence (IF) and karyotyping; respectively. Following the employment of this technique, a small piece of explant completely disappeared; while no dermis remained after 10 days.

Results

The quantity of HDFs harvested through this culture technique was reported at a normal level. The results of immunostaining also indicated that the isolated fibroblasts had expressed vimentin and fibronectin; whereas no cells had shown cytokeratin and epidermal marker. Moreover, karyotyping results for the fibroblasts isolated by the given technique revealed no chromosomal diversity after passage 20.

Conclusions

It was concluded that serial explant culture was an efficient technique for isolating HDFs from a small piece of skin in short-time periods; which could also preserve their normal morphology and molecular characteristics.

Microfluidic device for rapid digestion of tissues into cellular suspensions

The ability to harvest single cells from tissues is currently a bottleneck for cell-based diagnostic technologies, and remains crucial in the fields of tissue engineering and regenerative medicine. Tissues are typically broken down using proteolytic digestion and various mechanical treatments, but success has been limited due to long processing times, low yield, and high manual labor burden. Here, we present a novel microfluidic device that utilizes precision fluid flows to improve the speed and efficiency of tissue digestion. The microfluidic channels were designed to apply hydrodynamic shear forces at discrete locations on tissue specimens up to 1 cm in length and 1 mm in diameter, thereby accelerating digestion through hydrodynamic shear forces and improved enzyme-tissue contact. We show using animal organs that our digestion device with hydro-mincing capabilities was superior to conventional scalpel mincing and digestion based on recovery of DNA and viable single cells. Thus, our microfluidic digestion device can eliminate or reduce the need to mince tissue samples with a scalpel, while reducing sample processing time and preserving cell viability. Another advantage is that downstream microfluidic operations could be integrated to enable advanced cell processing and analysis capabilities. We envision our novel device being used in research and clinical settings to promote single cell-based analysis technologies, as well as to isolate primary, progenitor, and stem cells for use in the fields of tissue engineering and regenerative medicine.