v3.21.1
Consolidated Statements of Cash Flows - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Cash flows from operating activities:    
Net loss $ (10,721,691) $ (10,948,214)
Adjustments to reconcile net loss to net cash used in operating activities:    
Depreciation and amortization of property and equipment 33,929 103,165
Amortization of license agreements, patents and trademarks 36,464 41,347
Non-cash lease expense 120,186
Loss on disposal and abandonment of patents and equipment 5,654 60,104
Stock compensation expense 230,521 232,058
Value of stock issued in payment of employee bonuses 171,522
Value of stock issued in payment for services 70,201 14,800
Value of stock issued to 401(k) plan for employer matching contributions 39,834 19,588
Changes in operating assets and liabilities:    
Stock subscriptions and other receivables 839,020 (68,242)
Inventory (169,798)
Prepaid expenses and other assets 1,019,230 696,718
Accounts payable 49,648 687,351
Accrued and other liabilities 348,410 (195,989)
Lease liabilities (260,532)
Deferred revenue 13,609 2,584
Net cash used in operating activities (8,173,793) (9,354,730)
Cash flows from investing activities:    
Proceeds from sales of available-for-sale securities 400,000
Maturities of available-for-sale securities 400,000
(Payments for purchases) proceeds from disposal of equipment (135,881) 27,125
Proceeds from sales of equipment 1,042
Patent and trademark costs (277,989) (56,700)
Net cash (used in) provided by investing activities (412,828) 770,425
Cash flows from financing activities:    
Proceeds from issuance of preferred stock 5,975,000
Proceeds from issuance of common stock 4,442,560 7,086,915
Proceeds from note payable 366,000
Principal payments on notes payable (368,553) (359,061)
Net cash provided by financing activities 10,209,957 6,155,583
Net increase (decrease) in cash and cash equivalents 1,623,336 (2,428,722)
Cash and cash equivalents, beginning of period 1,047,159 3,475,881
Cash and cash equivalents, end of period 2,670,495 1,047,159
Preferred Stock Issuance Costs [Member]    
Cash flows from financing activities:    
Payment of stock issuance costs (55,050)
Common Stock Issuance Costs [Member]    
Cash flows from financing activities:    
Payment of stock issuance costs $ (150,000) $ (572,271)

Source