Development of morphine analgesia using biocompatible synthesized molecular imprinted hydrogel based on tragacanth gum

Abstract A novel molecular imprinted hydrogel using tragacanth gum (MITMIH) was synthesized for extending morphine analgesic efficacy by controlled release. The characterized MITMIH was used as a new morphine carrier that can increase analgesic time window after its single injection in mice. During in vitro optimization, the MITMIH showed maximum adsorption capacity (~113 mg g −1 ) at pH = 6.5 after 20 min immersion (400 μM initial morphine concentration, 10 mg MITMIH). During in vivo test, we examined the analgesic effect in mice by dissolving morphine in physiologic saline or by loading on MITMIH. The results of a single injection revealed that morphine‐loaded MITMIH shifted the time profile of morphine analgesia from 123.4 to 257.6 min. This indicates almost 100% efficacy in the controlled release of the drug during 5 h after the injection. Furthermore, cytotoxicity and mitochondrial membrane potential test was evaluated against normal rat kidney epithelial (NRK) and Rat Dermal Fibroblasts (RDF). The results confirmed that the MITMIH could be considered as a potential carrier increasing length of morphine analgesia after the first single injection without any cytotoxicity and negative effect on cell tissues. This may in turn reduce repeated use of the drug to achieve satisfactory analgesia in patients with chronic pain.