Self‐Healing Porous Microneedles Fabricated Via Cryogenic Micromoulding and Phase Separation for Efficient Loading and Sustained Delivery of Diverse Therapeutics

Abstract Sustained‐release drug delivery formulations are preferable for treating various diseases as they enhance and prolong efficacy, minimize adverse effects, and avoid frequent dosing. However, these formulations are associated with poor patient compliance, require trained personnel for administration, and involve harsh manufacturing conditions that compromise drug stability. Here, a self‐healing biodegradable porous microneedle (PMN) patch is reported for sustained drug delivery. The PMN patch is fabricated by a cryogenic micromoulding followed by phase separation, leading to formation of interconnected pores on the surface and internals of MNs. The pores with self‐healing feature enable the PMNs to load hydrophilic drugs with different molecular weights in a mild and efficient manner. The healed PMNs can easily penetrate into the skin under press and detach from the supporting substrate under shear, thereby acting as implantable drug reservoirs for achieving sustained release of drugs for at least 40 days. One‐time administration of desired therapeutics using the sustained‐release healed PMNs resulted in stronger and longer‐lasting efficacy in mitigating psoriasis and eliciting immunity compared to conventional methods with multiple administrations. The self‐healing PMN patch for self‐administrated and long‐acting drug delivery can eventually improve medication adherence in prophylactic and therapeutic protocols that typically require frequent dosages.