Fixed assets, net, summarized by major category, consist of the following (in thousands):


	December 31,
	2022		2021
Machinery and equipment	$	118,684	$	117,264
Leasehold improvements	61,302		59,740
Computer equipment and software	15,360		13,197
Office furniture and equipment	2,420		2,883
Construction in progress (1)	103,226		80,557
Total	300,992		273,641
Less: accumulated depreciation	(117,480)		(85,240)
Fixed assets, net	$	183,512	$	188,401
(1) The increase of $22.7 million in construction in progress is related to progress in the expansion of the Company’s manufacturing facilities, including an EXPAREL capacity expansion project at the Company’s Science Center Campus in San Diego, California and a ZILRETTA capital project at Thermo Fisher Scientific Pharma Services’s site in Swindon, England.

Depreciation expense for the years ended December 31, 2022, 2021 and 2020 was $34.2 million, $15.0 million and $12.0 million, respectively. During the years ended December 31, 2022, 2021 and 2020, the Company capitalized interest of $4.1 million, $3.9 million and $2.4 million, respectively. In 2022, the Company accelerated $10.5 million of depreciation expense for certain machinery and equipment for which no future economic benefit was identified.

As of December 31, 2022 and 2021, total fixed assets, net, includes leasehold improvements and manufacturing process equipment located outside of the U.S. in the amount of $44.7 million and $65.4 million, respectively.

As of December 31, 2022 and 2021, the Company had AROs of $3.3 million and $2.4 million, respectively, included in accrued expenses and other liabilities on its consolidated balance sheet, for costs associated with returning leased space to its original condition upon the termination of certain of its lease agreements.