Sentence:  Similar studies of rats have employed four different intracranial resorbable, slow sustained release systems&mdash; [...]. Such a slow-release device containing angiogenic factors could be placed on the pia mater covering the cerebral cortex and tested in persons with <WSD>senile</WSD> dementia in long term studies. 
Meaning of the word marked with <WSD> tags:  Of, or relating to old age.