The regenerative medicine industry is banking on cellular therapy to help regenerate tissues and restore function in clinical indications with high unmet needs. The mechanism of action, or how stem cells actually drive tissue regeneration, is still hotly debated – but it is likely a mixture of several actions (see item #6 in this post) that result from the cells producing multiple factors and releasing them into the local environment.
A more controlled method of driving tissue regeneration would be to have locally transplanted biomaterial-based devices present the soluble or insoluble factors at the desired site, without the use of cells. It is possible to present adhesion/migration signals from materials, as well as release a variety of soluble drugs or growth factors at different rates and times. If sufficient knowledge is acquired on how and why therapeutic cells work, and the mechanism is not dependent on long term cell engraftment, then it could be possible to engineer sophisticated biomaterial systems to provide necessary signals for driving tissue regeneration.
Not only is this possible, but proof of concept has been demonstrated with simple systems, and there are a variety of companies that are pursuing these strategies. These biomaterial companies include (there are several more):
- Kuros – modified PEGs and Fibrins, in clinical trials for bone regeneration
- 3D Matrix – self-assembly peptide hydrogels
- Biosyntech – cartilage regeneration, as well as bone and wound healing
- Fziomed – injectables for orthopedic applications (spine)
- Protein Polymer Technologies – engineered protein polymers
- Biomimetic Therapeutics – PDGF releasing biodegradable sponge for bone regeneration – currently on the market
- Medtronic – Infuse product; BMP releasing collagen sponge – market leader
- Orthovita – orthopedic nano-biomaterial company – markets as materials to use with cells
- Kensey Nash – orthopedic, dental, and cardiovascular products
- Genzyme Biomaterials – surgical sealants, hyaluronan-based lubricants (Synvisc)
- Symphony Medical – biopolymer based therapeutics
- TheraCardia – biopolymer based therapeutics – highlighted in Start-Up magazine in September 2007
While the manufacturing of biomaterial-based devices (surely considered combination products by the FDA) would be more straight forward than manufacturing cells for therapy, the regulatory landscape gets very cloudy as multiple signals are required for an intended therapeutic outcome. However, there are some companies that are moving forward with biomaterial therapies in traditionally cell-focused indications like cartilage, wound healing, and cardiac regeneration.
While I feel that cells will win out in the short term, biomaterial-based therapies will establish themselves (over time) in some clinical indications due to the relative simplicity of the products compared to cellular products. However, there will be room for all of these therapies in the marketplace. Long term success of therapeutic biomaterial companies will likely require business models that create near-term revenue so that they can stay in the game long enough to benefit from the technology trends. FMC has been working on innovative hybrid strategies (reagents, licensing, spin-outs) while trying to extract the value of their biopolymer products. Angiotech, Surmodics, and the Polymer Technology Group have created successful businesses around biomaterials by partnering with major device companies. It is possible that this will be required by other biomaterial companies to diversify outside of the therapy, unless they can achieve cash flow positive status from their clinical pipelines.
Other biomaterial links of interest:
The Regeneration Station 
This is a tremendously useful post. Thanks.