Microfluidic strategies for engineering oxygen-releasing biomaterials.

In the field of tissue engineering, local hypoxia in large-cell structures (larger than 1 mm3) poses a significant challenge. Oxygen-releasing biomaterials supply an innovative solution through oxygen ⁠ delivery in a sustained and controlled manner. Compared to traditional methods such as emulsion, sonication, and agitation, microfluidic technology offers distinct benefits for oxygen-releasing material production, including controllability, flexibility, and applicability. It holds enormous potential in the production of smart oxygen-releasing materials. This review comprehensively covers the fabrication and application of microfluidic-enabled oxygen-releasing biomaterials. To begin with, the physical mechanism of various microfluidic technologies and their differences in oxygen carrier preparation are explained. Then, the distinctions among diverse oxygen-releasing components in regards for oxygen-releasing mechanism, oxygen-carrying capacity, and duration of oxygen release are presented. Finally, the present obstacles and anticipated development trends are examined together with the application outcomes of oxygen-releasing biomaterials based on microfluidic technology in the biomedical area. STATEMENT OF SIGNIFICANCE: Oxygen is essential for sustaining life, and hypoxia (a condition of low oxygen) is a significant challenge in various diseases. Microfluidic-based oxygen-releasing biomaterials offer precise control and outstanding performance, providing unique advantages over traditional approaches for tissue engineering. However, comprehensive reviews on this topic are currently lacking. In this review, we provide a comprehensive analysis of various microfluidic technologies and their applications for developing oxygen-releasing biomaterials. We compare the characteristics of organic and inorganic oxygen-releasing biomaterials and highlight the latest advancements in microfluidic-enabled oxygen-releasing biomaterials for tissue engineering, wound healing, and drug delivery. This review may hold the potential to make a significant contribution to the field, with a profound impact on the scientific community.

Programmable Photoswitchable Microcapsules Enable Precise and Tailored Drug Delivery from Microfluidics.

The development of precision personalized medicine poses a significant need for the next generation of advanced diagnostic and therapeutic technologies, and one of the key challenges is the development of highly time-, space-, and dose-controllable drug delivery systems that respond to the complex physiopathology of patient populations. In response to this challenge, an increasing number of stimuli-responsive smart materials are integrated into biomaterial systems for precise targeted drug delivery. Among them, responsive microcapsules prepared by droplet microfluidics have received much attention. In this study, we present a UV-visible light cycling mediated photoswitchable microcapsule (PMC) with dynamic permeability-switching capability for precise and tailored drug release. The PMCs were fabricated using a programmable pulsed aerodynamic printing (PPAP) technique, encapsulating an aqueous core containing magnetic nanoparticles and the drug doxorubicin (DOX) within a poly(lactic-co-glycolic acid) (PLGA) composite shell modified by PEG-b-PSPA. Selective irradiation of PMCs with ultraviolet (UV) or visible light (Vis) allows for high-precision time-, space-, and dose-controlled release of the therapeutic agent. An experimentally validated theoretical model was developed to describe the drug release pattern, holding promise for future customized programmable drug release applications. The therapeutic efficacy and value of patternable cancer cell treatment activated by UV radiation is demonstrated by our experimental results. After in vitro transcatheter arterial chemoembolization (TACE), PMCs can be removed by external magnetic fields to mitigate potential side effects. Our findings demonstrate that PMCs have the potential to integrate embolization, on-demand drug delivery, magnetic actuation, and imaging properties, highlighting their immense potential for tailored drug delivery and embolic therapy.