4. Prepaid Expenses and Other Current Assets (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Prepaid expenses and other current assets	$ 336,422	$ 449,840
Collaborative Development Agreement [Member]
Prepaid expenses and other current assets	47,883	95,766
Prepaid Rent [Member]
Prepaid expenses and other current assets	32,956	31,773
Vendor Advances [Member]
Prepaid expenses and other current assets	5,659	7,867
Prepaid Service Agreements [Member]
Prepaid expenses and other current assets	138,767	174,920
Employee advance and other payroll related items [Member]
Prepaid expenses and other current assets	18,937	16,208
Other Prepaid Expenses and Current Assets [Member]
Prepaid expenses and other current assets	$ 92,220	$ 123,306