Emerging interest in research of polymeric biomaterials towards human health has intrigued me to pursue my graduate research, primarily towards a few biomedical applications like radiation dosimetry, drug & gene delivery systems. Although Radiotherapy remains a foundation of cancer treatment procedures in clinic; overdosing of radiation can induce toxicity to sensitive organs and underexposure can lead to low efficacies of tumor treatment. Commercial sensors consist of several intrinsic disadvantages due to their sensitivity to heat and light, long processing times, and high costs. For real-time dose detection, a novel colorimetric hydrogel sensor was developed with formation of maroon-colored gold nanoparticles (templated by a variety of surfactants and amino acids) within an agarose-based polymeric hydrogel, upon exposure of ionizing radiation. Translational potential of sensor was demonstrated using anthropomorphic phantoms and in live canine patients undergoing radiotherapy treatments by qualitatively and quantitatively measuring the delivered dose. Combination therapy by simultaneously using drug & gene delivery with a single multifunctional carrier can lead to novel treatment modalities for various diseases like Cancer, Alzheimer etc. A library of lipid-based Aminoglycoside-derived cationic self-assembling polymer nanoparticles (LPNs) was developed with size ranging from (50-150) nm. Lead LPNs showed great potential for concurrent delivery of nucleic acids along with small molecule drug such as histone deacetylase (HDAC) inhibitor, AR-42 as a combination treatment to cancer cells.