As an intelligent polymer material, pH-sensitive hydrogels exhibit the capability to dynamically sense alterations in ambient pH levels and subsequently initiate corresponding physical or chemical responses, including swelling, contraction, degradation, or ion exchange. Given the significant pH variations inherent in human pathophysiological microenvironments, particularly in tumor tissues, inflammatory lesions, and the gastrointestinal system, these smart materials demonstrate remarkable application potential across diverse domains such as targeted drug delivery systems, regenerative medicine engineering, biosensing, and disease diagnostics. Recent breakthroughs in nanotechnology and precision medicine have substantially propelled advancements in the design and application of pH-responsive hydrogels. This review systematically elaborates on the current research progress and future challenges regarding pH-responsive hydrogels in biomedical applications, with particular emphasis on their stimulus–response mechanisms, fabrication methodologies, multifunctional integration strategies, and application scenarios.

Neurological diseases, which include various neurodegenerative disorders, not only impair patients’ physical health but also impact their psychological and social functions. It is particularly urgent to seek effective prevention and treatment strategies for neurological diseases. Alpiniae oxyphyllae Fructus (AOF), a traditional Chinese medicinal herb, has been widely used in treating urinary, digestive, and neurological disorders. Contemporary medical research has demonstrated that AOF exerts neuroprotective effects through multiple mechanisms, including by inhibiting neuronal apoptosis, alleviating neuroinflammation, reducing oxidative stress, and regulating nerve cell dynamic balance. In recent years, substantial advancements have been achieved in investigations concerning the neuroprotective effects and underlying mechanisms of AOF, alongside significant breakthroughs in its clinical applications. This review systematically summarizes the neuroprotective effects of AOF and delineates its clinical applications, thereby offering valuable reference and guidance for the prevention and treatment of neurological diseases using AOF.

Alzheimer’s disease (AD) is characterized by Tau hyperphosphorylation, β-amyloid (Aβ) accumulation, and progressive neuronal loss. Gastrodia elata (G. elata), a traditional Chinese medicine with well-established neuroprotective properties, was investigated. Two G. elata-derived miRNAs, Gas-miR04-3p and Gas-miR19-5p, were identified as regulators of JNK3. By means of Western blot, RT-qPCR, and assessments of antioxidant indices, it was demonstrated that Gas-miR04-3p and Gas-miR19-5p can suppress JNK3 expression, reduce Tau phosphorylation at Ser202 and Ser396, enhance antioxidant capacity, and attenuate apoptosis in AD-related cellular and molecular pathology models. These miRNAs were also detectable in murine brain tissues following oral administration of total RNA extracted from G. elata. Their administration was associated with decreased JNK3 activation, alleviated Tau hyperphosphorylation, and improved expression of apoptosis-related proteins in AD mouse models. These results suggest that G. elata miRNAs may exert neuroprotective effects through regulation of JNK3 signaling, thereby attenuating Tau-related pathological changes and neuronal injury in AD-related models.