Tissue engineering--body parts from the Petri dish

History of regenerative medicine: looking backwards to move forwards

If the song by the international popstar Sting is to be relied upon, 'History will teach us nothing'. At the risk of contradicting a one-time schoolteacher, I believe the reverse is true for regenerative medicine. In fact, I think we dismiss the past at our peril. In this review, I aim to trace the history of regenerative medicine to date. I will examine parallels with other areas of medicine and show how commercial, technical and socio/economic factors have influenced the pace and direction of the sector's evolution. I will discuss how, by learning from the past, those involved in regenerative medicine are reinventing their sector for the better. In conclusion, I will evaluate the current state of the industry, suggest what the future may hold and explain why I believe regenerative medicine is about to 'come of age'.

A New Method of Costal Cartilage Harvest for Total Auricular Reconstruction: Part II. Evaluation and Analysis of the Regenerated Costal Cartilage

BACKGROUND

The authors established the hypothesis that chest wall deformity can be absolutely avoided by leaving the perichondrium completely intact at the donor site for cartilage regeneration. As described in Part I, on the new method of costal cartilage harvest, the authors were able to confirm regeneration of cartilage visually and with palpation at 6 months postoperatively.

METHODS

The regenerated cartilage of four patients at 6, 8, 10, and 12 months, respectively, after the first-stage operation was harvested for morphological and histological evaluation and analyses during the second-stage operation.

RESULTS

Morphological findings revealed the regenerated cartilage to be cylindrical in shape, and histological findings confirmed transformation of regenerated cartilage to normal costal (hyaline) cartilage with respect to time.

CONCLUSIONS

The authors' findings revealed that not only is postoperative chest wall deformity avoided with the new method of costal cartilage harvest but the major scientific merit lies in the fact that the regenerated cartilage can be used as demonstrated during the second-stage operation. This gives hope to bilateral microtia patients requiring secondary auricular reconstruction, which was thought to be impossible because of the lack of costal cartilage for fabrication of a three-dimensional costal cartilage framework.

The Human Host Defense Peptide LL37/hCAP Accelerates Angiogenesis in PEGT/PBT Biopolymers

INTRODUCTION

Antimicrobial peptides are effector molecules of the innate immune response and contribute to host defense and inflammation. This study was designed to evaluate neovascularization in biopolymers after instillation with LL37 of angiogenesis in the dorsal skinfold chamber in mice.

MATERIAL AND METHODS

The host defense peptide human cathelicicin LL37 was tested for in vitro antimicrobial activity in a bilayer radial diffusion assay. For in vivo testing, 4 different concentrations of LL37 or carrier control were instilled into a biopolymer, then inserted into the dorsal skinfold chamber in Balb/c mice. Standard microcirculatory parameters were assessed over 24 days' follow-up.

RESULTS

LL37 showed broad-spectrum antimicrobial activity against gram-positive and -negative bacteria. The LL37 treatment of the biopolymer accelerated the onset of neovascularization by 6 days compared with the carrier control (P < 0.01).

CONCLUSION

This study demonstrated that LL37 has antimicrobial activity and is important for early support of neoangiogenesis in biopolymers. The multifunctional human host defense peptide LL37 has potential as an adjunct for tissue engineering.