Commitments and Contingencies - Additional Information (Detail) - USD ($)
 1 Months Ended 12 Months Ended
Sep. 30, 2015
Jun. 30, 2012
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2004
Loss Contingencies [Line Items]          
Rent expense under operating lease agreements     $ 1,116,000 $ 900,000  
Research and development expense     23,243,000 $ 26,037,000  
Tissue Regeneration License Agreement [Member]          
Loss Contingencies [Line Items]          
Research and development expense     709,000    
One-time payment amount     $ 300,000    
Percentage of royalty offsetting     50.00%    
Hydrogel License Agreement [Member]          
Loss Contingencies [Line Items]          
Research and development expense     $ 3,200,000    
One-time payment amount     3,000,000    
Plasmid License Agreement [Member]          
Loss Contingencies [Line Items]          
Non-refundable license fee     2,000    
Minimum [Member] | Tissue Regeneration License Agreement [Member]          
Loss Contingencies [Line Items]          
Non-refundable royalty fee     10,000    
Maximum [Member] | Waltham [Member]          
Loss Contingencies [Line Items]          
Construction allowance to total cost of tenant improvements     3,184,000    
Maximum [Member] | Lexington [Member]          
Loss Contingencies [Line Items]          
Construction allowance to total cost of tenant improvements     996,000    
Tissue Processor Sub License Agreement [Member]          
Loss Contingencies [Line Items]          
Research and development expense     941,000    
Reimbursement for development cost   $ 250,000      
Potential milestone payments     200,000    
Tissue Processor Sub License Agreement [Member] | Minimum [Member]          
Loss Contingencies [Line Items]          
Non-refundable royalty fee     $ 20,000    
OCS Agreement [Member]          
Loss Contingencies [Line Items]          
Accrued and received grants, aggregate         $ 1,100,000
OCS Agreement [Member] | Minimum [Member]          
Loss Contingencies [Line Items]          
Royalties payment, rate     3.00%    
OCS Agreement [Member] | Maximum [Member]          
Loss Contingencies [Line Items]          
Royalties payment, rate     5.00%    
Royalty payment percentage as percentage of grant received     300.00%    
Engineering Agreement [Member]          
Loss Contingencies [Line Items]          
Purchase amount required to pay     $ 377,000    
Purchase amount, remaining to be paid     190,000    
Collagen Supply Agreement [Member]          
Loss Contingencies [Line Items]          
Purchase amount, remaining to be paid     30,000    
Minimum amount of material and/or services $ 150,000        
Non-refundable payment     121,000    
Amount paid to suppliers     $ 93,000    
Initial term of the agreement 3 years        
Supplier agreement description     The initial term of the agreement is three years and will automatically renew from year to year thereafter unless otherwise terminated with at least 180 days' notice by either party.    
Operating lease expiration year     2016