Sea Cucumber-Inspired Microneedle Nerve Guidance Conduit for Synergistically Inhibiting Muscle Atrophy and Promoting Nerve Regeneration.

Muscle atrophy resulting from peripheral nerve injury (PNI) poses a threat to a patient's mobility and sensitivity. However, an effective method to inhibit muscle atrophy following PNI remains elusive. Drawing inspiration from the sea cucumber, we have integrated microneedles (MNs) and microchannel technology into nerve guidance conduits (NGCs) to develop bionic microneedle NGCs (MNGCs) that emulate the structure and piezoelectric function of sea cucumbers. Morphologically, MNGCs feature an outer surface with outward-pointing needle tips capable of applying electrical stimulation to denervated muscles. Simultaneously, the interior contains microchannels designed to guide the migration of Schwann cells (SCs). Physiologically, the incorporation of conductive reduced graphene oxide and piezoelectric zinc oxide nanoparticles into the polycaprolactone scaffold enhances conductivity and piezoelectric properties, facilitating SCs' migration, myelin regeneration, axon growth, and the restoration of neuromuscular function. These combined effects ultimately lead to the inhibition of muscle atrophy and the restoration of nerve function. Consequently, the concept of the synergistic effect of inhibiting muscle atrophy and promoting nerve regeneration has the capacity to transform the traditional approach to PNI repair and find broad applications in PNI repair.

3D printing of Rg3-loaded hydrogel scaffolds: anti-inflammatory and scar-formation related collagen inhibitory effects for scar-free wound healing.

During the process of wound healing, the stimulation of inflammatory factors often leads to abnormal proliferation of blood vessels and collagen, ultimately resulting in scar formation. To address this challenge, we fabricate a novel dermal extracellular matrix (DECM) hydrogel scaffold loaded with ginsenoside Rg3 (Rg3) using 3D printing technology. Mesoporous silica nanoparticles (MSNs) are introduced into the system to encase the Rg3 to control its release rate and enhance its bioavailability. We systematically evaluate the biological, physicochemical, and wound healing properties of this scaffold. In vitro studies demonstrate that the hydrogel exhibits excellent biocompatibility and solid-like rheological properties, ensuring its successful printing. In vivo studies reveal that the composite hydrogel scaffolds effectively accelerate wound healing and achieve scar-free wound healing within three weeks. Histological and immunohistochemical (IHC) analyses show that the composite hydrogel scaffolds reduce the inflammatory response and inhibit excessive collagen accumulation. These combined effects underscore the potential of our approach in effectively inhibiting scar formation.

3D printing nacre powder/sodium alginate scaffold loaded with PRF promotes bone tissue repair and regeneration.

Bone defects are a common complication of bone diseases, which often affect the quality of life and mental health of patients. The use of biomimetic bone scaffolds loaded with bioactive substances has become a focal point in the research on bone defect repair. In this study, composite scaffolds resembling bone tissue were created using nacre powder (NP) and sodium alginate (SA) through 3D printing. These scaffolds exhibit several physiological structural and mechanical characteristics of bone tissue, such as suitable porosity, an appropriate pore size, applicable degradation performance and satisfying the mechanical requirements of cancellous bone, etc. Then, platelet-rich fibrin (PRF), containing a mass of growth factors, was loaded on the NP/SA scaffolds. This was aimed to fully maximize the synergistic effect with NP, thereby accelerating bone tissue regeneration. Overall, this study marks the first instance of preparing a bionic bone structure scaffold containing NP by 3D printing technology, which is combined with PRF to further accelerate bone regeneration. These findings offer a new treatment strategy for bone tissue regeneration in clinical applications.