Figure 4: Cellular metabolic activity/proliferation in the presence and absence of alpha ketoglutarate (α-KG) was analyzed by MTT assay. Neuro 2a metabolic activity/proliferation on 2-D and 3-D control (α-KG absent) as well as α-KG containing samples wherein α-KG was delivered in the following three different ways: (i) exogenously in free form in 2-D, (ii) chitosan or gelatin microspheres containing α-KG in both 2-D and 3-D system, and (iii) α-KG containing chitosan or gelatin microspheres incorporated in the synthesized chitosan-gelatin-polypyrrole cryogel were analyzed. All the experiments were performed in triplicates, and the Student’s-t test was performed to obtain the value. .