Xin Huang

Microneedles (MNs), characterized by their micron-sized sharp tips, can painlessly penetrate the skin and have shown significant potential in disease treatment and biosensing. With the development of artificial intelligence (AI), the design and application of MNs have experienced substantial innovation aided by machine learning (ML). This review begins with a brief introduction to the concept of ML and its current stage of development. Subsequently, the design principles and fabrication methods of MNs are explored, demonstrating the critical role of ML in optimizing their design and preparation. Integration between ML and the applications of MNs in therapy and sensing were further discussed. Finally, we outline the challenges and prospects of machine learning-assisted MN technology, aiming to advance its practical application and development in the field of smart diagnosis and treatment.

The patch-based delivery system has been a promising therapeutic approach for treating various vascular diseases. However, conventional methods face several challenges, including labor-intensive and time-consuming processes associated with patch fabrication or factor incorporation, inadequate physical properties, and uncontrolled release of factors. These limitations restrict the potential applications in clinical settings. To overcome these issues, we propose a novel core-shell-shaped droplet patch system called an angiogenic patch (AP). Our system offers several distinct advantages over conventional patches. It enables a rapid and straightforward fabrication process utilizing only two biodegradable ingredients [alginate and ε-poly(l-lysine)], ensuring minimal toxicity. Moreover, the AP exhibits excellent physical integrity to match and withstand physiological mechanics and allows for customizable patch dimensions tailored to individual patients' pathological conditions. Notably, the AP enables facile loading of angiogenic cytokines during patch fabrication, allowing sustained release at a controlled rate through tunable network cross-linking. Subsequently, the AP, delivering a precisely formulated cocktail of angiogenic cytokines (VEGF, bFGF, EGF, and IGF), demonstrated significant effects on endothelial cell functions (migration and tubule formation) and survival under pathological conditions simulating ischemic injury. Likewise, in in vivo experiments using a mouse model of hindlimb ischemia, the AP encapsulating the angiogenic cocktail effectively restored blood flow following an ischemic insult, promoting muscle regeneration and preventing limb loss. With its simplicity and rapid processability, user-friendly applicability, physical tunability, and the ability to efficiently load and control the delivery of angiogenic factors, the AP holds great promise as a therapeutic means for treating patients with ischemic diseases.

Supramolecular organogel coatings that can disinfect the deposited microbial pathogens are emerging as an effective vehicle to prevent pathogen transmission. However, the development of anti-pathogen supramolecular adhesives with mechanical robustness and controlled oil inclusion is technically challenging. Here, we report supramolecular adhesives with mechanical integrity and robust interfacial adhesion over a wide range of biogenic antimicrobial oil. Bifunctional monomers are synthesized and assembled into linear polymers with semicrystalline stackings through hierarchical hydrogen bonds, where incorporated bioactive oil could regulate the semicrystalline stackings into nanosized crystalline domains through intermolecular hydrogen bonds. The abundant bonding motifs provided by the supramolecular cross-linked networks could accommodate oil molecules with high inclusion capability and provide more interfacial binding sites with high adhesion strength, and the nanosized crystalline domains could stabilize the organogel network and compensate for the interactions with oil molecules to enhance structural and mechanical stability. In addition, rapid healing, robust adhesion, and antimicrobial and antiviral properties of the resultant organogel coatings are demonstrated. This study paves the way for the development of high-performance antimicrobial supramolecular adhesives with controlled oil inclusion, showing potential applications in soft robotics, tissue engineering, and biomedical devices.

Using antimicrobial coatings to control the spread of pathogenic microbes is appreciated in public and healthcare settings, but the performance of most antimicrobial coatings could not fulfill the increasing requirements, particularly the ease of preparation, high durability, rapid response, and high killing efficiency. Herein, we develop a new type of mechano-induced assembly of nanocomposite coating by simple “Press-N-Go” procedures on various substrates such as glassware, gloves, and fabrics, in which the coating shows strong adhesion, high shear stability, and high stiffness, making it durable in daily use to withstand common mechanical deformation and scratches. The coating also shows remarkable disinfection effectiveness over 99.9% to clinically significant multiple drug-resistant bacterial pathogens upon only 6 s near-infrared irradiation, which can be further improved to over 99.9999% upon another 6 s treatment. We envision that the coating can provide convenience and values to control pathogen spread for easily contaminated substrates in high-risk areas.

All‐aqueous droplets demand structural and functional robustness to provide tailored microenvironments for various biomedical applications. Inspired by the structural supporting properties of eggshell membranes, all‐aqueous droplets with robust shells featuring optical transparence, compound permeability, and swelling resistance are developed. The dense coacervate shell encapsulates sodium alginate (Alg) droplets in a continuous ε‐poly‐l‐lysine (ε‐PL) solution, via diffusion‐controlled interfacial coacervation between Alg and ε‐PL. Benefiting from the permeability of the coacervate shell, the core of the droplet presents embryo‐like stiffness‐responsiveness between the fluid and gel states via the perception of external microenvironment. Particularly, in a benchmarking comparison with Alg‐Ca²⁺ hydrogel, the coacervate encapsulation presents boosted durability, mechanical robustness, and selective permeability in diverse conditions. This design strategy not only deepens the understanding on the design of all‐aqueous droplets with adaptive functions via one‐step interfacial coacervation between two miscible aqueous phases, but also broadens their feasibility as integrated platforms for biomedical applications.

Inspired by the mucus, which provides an ideal supramolecular model and whose fluid-like (viscous) and solid-like (elastic) behaviors can be adjusted to meet different physiological requirements, we report oil-regulated supramolecular adhesives by co-assembly of polyurea oligomers and carvacrol oils. The adhesive is crosslinked by weak but abundant hydrogen bonds which can be regulated by the incorporated carvacrol oils through the competition of intermolecular hydrogen bonds, presenting a unique set of mucus-mimicking features including oil-regulated mechanics, processability, reusable adhesivity, and extreme longevity in both air and water. Owing to the intrinsic bactericidal effect of the carvacrol oils, the developed adhesives can serve as potent antibacterial coatings with both rapid contact killing (99.9% killing within 15 minutes) and long-term controlled release abilities (up to 70 days), enabling versatile antibacterial applications in diverse conditions. We envision that these adhesives will be useful in buildings and architectures, community and public facilities, food storage and packaging technologies, functional textiles and practical biomedical fields.

Precise and robust manipulation of air bubbles will favor intense demands from governing processes of chemical reactions to enhancing transportation efficiency in multiphase engineering systems. Inspired by the working mechanism of mucous lining in lung alveoli, the elastic liquid-infused material (eLIM) is constructed by infiltrating an interconnected porous elastomer with a low-surface-energy lining liquid. With the help of the lining liquid, the pore pressure of the interconnected channels in eLIM can be reversibly regulated under mechanical stretching, balancing the capillary pressure in the channels with diverse radii and allowing gas flow in these channels. Therefore, air bubbles could be transported in and across the eLIM, showing on-demand control on the bubble contact angle, merging and splitting in an active and precise manner. The robust manipulation strategies on air bubbles can find applications in bioreactors and many other bubble-involved processes.