I see that Tengion, Anthony Atala's tissue engineering company, has filed to go public.

Tengion, which discovers, develops, manufactures and commercializes a range of replacement organs and tissues, or neo-organs and neo-tissues, filed on Thursday with the SEC to raise up to $40 million in an initial public offering. ... The East Norriton, PA-based company, which was founded in 2003 and has yet to generate revenue, plans to list on the NASDAQ under the symbol TNGN. Its product candidates focus on combining technology with the body's intrinsic capacity to regenerate tissue to address urologic, renal, gastrointestinal and vascular diseases; there are six candidates in the pipeline. Net proceeds from the deal will be used for research and development, repayment of debt and general corporate purposes.

I believe this should be taken as an indicator of future strength in the market for tissue engineering, and likewise in progress towards growing a wider range of replacement organs from a patient's own cells. Why? Because especially unpleasant financial and corporate governance legislation of recent years - even by the standards of US bureaucrats - has squashed the US IPO market down to a shadow of its former self. The costs and liabilities placed on public companies and their officers are enormous now in comparison to ten or twenty years ago. To hold an IPO today you either have to be mad or very confident indeed in your ability to generate high levels of revenue; here, I think the latter is much more likely.