Selected Balance Sheet Components

Inventory as of December 31, 2016 and 2015:



(In thousands)	2016		2015
Raw materials	$	3,214	$	1,228
Work-in-process	257		131
Finished goods	17		20
Inventory	$	3,488	$	1,379

Property and Equipment, net as of December 31, 2016 and 2015:



(In thousands)	2016			2015
Machinery and equipment	$	3,150		$	3,280
Furniture, fixtures and office equipment	931			931
Computer equipment and software	3,147			2,662
Leasehold improvements	3,332			2,393
Construction in process	408			421
	10,968			9,687
Less accumulated depreciation	(7,093		)	(5,638		)
Property and Equipment	$	3,875		$	4,049

Depreciation expense for the years ended December 31, 2016, 2015 and 2014 were $1.6 million, $1.3 million, and $0.8 million, respectively.

Intangible assets, net as of December 31, 2016 and 2015:



(In thousands)	2016		2015
Commercial rights	$	—	$	3,360
Less accumulated amortization	—		(443		)
Intangible assets	$	—	$	2,917

Upon the approval of MACI in December 2016 and the replacement of Carticel with MACI, it was determined that the Carticel commercial rights intangible asset was fully impaired as of December 31, 2016. The value of the intangible assets was determined using the income approach based on projected cash flows attributed to the commercial rights. Amortization expense was $0.3 million, $0.3 million and $0.2 million for the years ended December 31, 2016, 2015 and 2014, respectively.

Accrued Expenses as of December 31, 2016 and 2015:



(In thousands)	2016		2015
Bonus	$	2,433	$	1,956
Employee related accruals	1,668		1,341
Accrued expenses	422		75
Other	—		231
Accrued expenses	$	4,523	$	3,603