<p>The hydrophilic network of superabsorbent polymers (SAPs) enables absorption and retention of a large volume of fluids relative to their own mass. However, the extensive use of synthetic SAPs raises serious environmental concerns regarding their unsustainability and unsafe production. Utilization of environment-friendly biodegradable alternatives as raw materials will greatly increase the sustainability of these products. This study focuses on developing novel, bio-based SAPs from low-cost plant-derived functional components for biomedical applications. Macroporous, interconnected cryogels were successfully fabricated using carboxymethyl cellulose (CMC) as the primary substrate, and <i>Moringa oleifera</i> fibers and rice husk biochar as sustainable augmentations to enhance functionality. The developed bio-based SAPs containing both the functional components exhibited highest swelling capacity (~ 16 gg^− 1), acceptable mechanical strength (~ 743.9 ± 59 KPa), and enhanced bioactivity in terms of highest cell proliferation with an increasing trend from day 1 to day 7. The degradation profiles were environment-dependent, wherein 63.6 ± 0.04% degradation was observed in phosphate buffered saline in 30 days, 57 ± 0.06% in soil and 52 ± 0.01% in compost after 15 days. Based on these properties, these functional and biodegradable SAPs have the potential to be applied for diverse biomedical and environmental applications, including in menstrual sanitary products, wound dressings, etc., wherein they are expected to reduce the dependency on petroleum-based SAPs. This work highlights a sustainable approach to developing alternative bio-based polymers with sutainable augmentations to improve biological performance via functionality enrichment in terms of swelling ratio, mechanical strength, rate of biodegradation and cell viability for biomedical applications and environmental benefits.</p> Graphical abstract <p></p>