Local anesthetics (LAs) have been indispensable in clinical pain management, yet their limitations, such as short duration of action and systemic toxicity, necessitate improved delivery strategies. Hydrogels, with their biocompatibility, tunable properties, and ability to modulate drug release, have been extensively explored as platforms for enhancing LA efficacy and safety. This narrative review explores the historical development of LAs, their physicochemical properties, and clinical applications, providing a foundation for understanding the integration of hydrogels in anesthetic delivery. Advances in thermoresponsive, stimuli-responsive, and multifunctional hydrogels have demonstrated significant potential in prolonging analgesia and reducing systemic exposure in preclinical studies, while early clinical findings highlight the feasibility of thermoresponsive hydrogel formulations. Despite these advancements, challenges such as burst release, mechanical instability, and regulatory considerations remain critical barriers to clinical translation. Emerging innovations, including nanocomposite hydrogels, biofunctionalized matrices, and smart materials, offer potential solutions to these limitations. Future research should focus on optimizing hydrogel formulations, expanding clinical validation, and integrating advanced fabrication technologies such as 3D printing and artificial intelligence-driven design to enhance personalized pain management. By bridging materials science and anesthetic pharmacology, this review provides a comprehensive perspective on current trends and future directions in hydrogel-based LA delivery systems.

Multifunctional hydrogels represent an emerging technological advancement in cancer therapeutics, integrating diagnostic imaging capabilities with therapeutic modalities into comprehensive, multifunctional systems. These hydrogels exhibit exceptional biocompatibility, biodegradability, high water retention capacity, and tunable mechanical properties, enabling precise drug delivery while minimizing systemic side effects. Recent innovations in stimuli-responsive components facilitate intelligent, controlled drug release mechanisms triggered by various stimuli, including changes in pH, temperature, magnetic fields, and near-infrared irradiation. Incorporating diagnostic imaging agents, such as magnetic nanoparticles, fluorescent dyes, and radiolabeled isotopes, substantially improves tumor visualization and real-time therapeutic monitoring. Multifunctional hydrogels effectively integrate chemotherapy, photothermal therapy, photodynamic therapy, immunotherapy, and their synergistic combinations, demonstrating superior therapeutic outcomes compared to conventional methods. Particularly, injectable and in situ-forming hydrogels provide sustained local drug delivery postoperatively, effectively reducing tumor recurrence. However, challenges persist, including initial burst release, mechanical instability, regulatory barriers, and scalability concerns. Current research emphasizes advanced nanocomposite formulations, biofunctionalization strategies, and innovative manufacturing technologies like 3D bioprinting to facilitate clinical translation. This review comprehensively summarizes recent advancements, clinical applications, and future perspectives of multifunctional hydrogel systems for enhanced cancer treatment, underscoring their potential to revolutionize personalized oncology.

Laparoscopic surgery reduces tissue trauma and accelerates recovery, but postoperative pain remains a concern. Opioids are effective but have adverse effects, highlighting the need for multimodal analgesia. Nefopam, a non-opioid analgesic, provides pain relief without respiratory depression or dependence. This study aims to investigate the efficacy of intravenous nefopam combined with a transversus abdominis plane (TAP) block in living liver donors undergoing laparoscopic hepatectomy. This retrospective cohort analysis was conducted on 452 adult living donors who underwent laparoscopic hepatectomy with a TAP block between August 2013 and August 2018 at a single tertiary medical center. After propensity score matching, 296 patients were included, with 148 in the nefopam group and 148 in the non-nefopam group. The primary outcomes assessed were pain scores using the Numeric Rating Scale (NRS) at 1, 4, 8, 12, and 24 h postoperatively, opioid consumption, postoperative nausea and vomiting, and nefopam-related adverse effects. Nefopam significantly reduced NRS at 1, 4, and 8 h postoperatively (p < 0.001) and decreased fentanyl use in the post-anesthesia care unit (26.0 ± 32.2 μg vs. 60.5 ± 37.9 μg, p < 0.001) and total intravenous patient-controlled analgesia volume (p < 0.001). The incidence of postoperative nausea and vomiting and severe opioid-related complications did not differ between groups. Nefopam-related side effects were mild and self-limiting. Nefopam combined with a TAP block effectively reduces postoperative pain and opioid consumption in living liver donors, supporting its role in multimodal analgesia. Further research is needed to explore its broader applications.

Effective postoperative pain management is crucial for optimizing recovery and clinical outcomes in living donor kidney transplantation (LDKT). This retrospective study compared the efficacy and safety of transversus abdominis plane (TAP) block and local wound infiltration (LWI) for postoperative analgesia. A total of 524 LDKT recipients, matched through propensity scoring, were analyzed (262 per group). Pain intensity was assessed using the visual analog scale (VAS) at multiple postoperative time points, while opioid consumption was evaluated based on intravenous patient-controlled analgesia (IV-PCA) usage and rescue fentanyl doses. The TAP block group had significantly lower VAS pain scores at 1, 4, and 8 h postoperatively (p < 0.001) and required fewer opioids, as evidenced by reduced IV-PCA usage (55.9 ± 10.2 mL vs. 69.7 ± 18.2 mL; p < 0.001) and lower rescue fentanyl doses (67.7 ± 30.6 µg vs. 119.1 ± 71.8 µg; p < 0.001). Despite these differences in analgesic efficacy, no significant differences were observed between the groups in terms of postoperative nausea and vomiting or complications such as systemic toxicity and nerve injury. These findings suggest that the TAP block provides more effective early postoperative pain relief and reduces opioid requirements without increasing adverse events. Given its favorable safety profile and effectiveness, the TAP block is a valuable component of multimodal analgesia in LDKT recipients, supporting enhanced recovery while minimizing opioid-related complications.

In patients undergoing living donor liver transplantation (LDLT) with immediate postoperative extubation in the operating room (OR), rapid recovery of consciousness and spontaneous ventilation are essential, requiring effective analgesia without compromising respiratory function. This study evaluated whether intraoperative nefopam administration improves early postoperative pain control and reduces opioid consumption in this physiologically distinct population. A retrospective cohort of 376 adult LDLT recipients who met the criteria for OR extubation was analyzed. After propensity score matching, 182 patients who received intraoperative nefopam were compared with 182 matched controls. Pain intensity was measured using the visual analog scale (VAS), and total fentanyl consumption and opioid-related complications were recorded over the first 24 h postoperatively. Nefopam administration was associated with significantly lower VAS scores during the first 12 h after surgery (p < 0.001) and reduced 24 h fentanyl consumption (53.2 ± 20.8 mL vs. 58.6 ± 27.5 mL, p = 0.035). No serious adverse effects related to nefopam were observed. The incidence of postoperative nausea and vomiting did not differ significantly between the groups. These findings indicate that nefopam offers effective early analgesia and an opioid-sparing effect in LDLT recipients undergoing OR extubation, suggesting its clinical utility as a component of multimodal analgesia in this high-risk group. Although the reduction in opioid use did not translate into a decreased incidence of opioid-related complications, the favorable safety profile and analgesic efficacy of nefopam support further investigation through prospective trials to define its role in enhanced recovery protocols for OR-extubated LDLT recipients.