Development of magnetic poly(L-lactic Acid) nanofibrous microspheres for transporting and delivering targeted cells

A facile strategy for the preparation of polylactide nano-microspheres with enhanced stereo-complexations

Stereo-complexed polylactide (sc-PLA) nano-microspheres were separated by adding poor solvent to the poly(l-lactide) (PLLA)/poly(d-lactide) (PDLA) blend solution. The effects of different process parameters (concentration, processing method, ratio of PLLA/PDLA blend solution to poor solvent) on the microsphere particle size were investigated. The microscopic morphology, crystallinity, and thermal properties were investigated by Fourier transform infrared spectroscopy, differential scanning calorimetry, two-dimensional wide-angle X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The results indicated that when the concentration reached 10 wt% and the PLLA/PDLA blend solution to poor solvent ratio was 1 : 5, the sc-PLA nano-microspheres exhibited more regular shape, good sphericity and uniform particle size, and the highest crystallinity. Additionally, the degree of crystallinity of the stereo-complexed crystals was as high as 39.60%, the rate of stereo-complexation was 99.65%, and the melting temperature reached 220 °C, indicating notable improvement in the crystallization and thermal properties. The sc-PLA nano-microspheres obtained in this research could be used as a nucleating agent for fibers and drug delivery carrier, and the sc-PLA nano-microspheres have broad application prospects in the textile and biomedical fields.

Stimuli-responsive microcarriers and their application in tissue repair: A review of magnetic and electroactive microcarrier

Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells, drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct a good microenvironment for tissue repair. In order to achieve more ideal performance and face more complex tissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond to external stimuli. These microcarriers have the functions of directional movement, targeted enrichment, material release control, and providing signals conducive to tissue repair. Given the high controllability and designability of magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in this review. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed. In summary, through the design with clinical translation ability, meaningful and comprehensive experimental characterization, and in-depth study and application of tissue repair mechanisms, stimuli-responsive microcarriers have great potential in tissue repair.

Biomaterial engineering for cell transplantation

The current paradigm of medicine is mostly designed to block or prevent pathological events. Once the disease-led tissue damage occurs, the limited endogenous regeneration may lead to depletion or loss of function for cells in the tissues. Cell therapy is rapidly evolving and influencing the field of medicine, where in some instances attempts to address cell loss in the body. Due to their biological function, engineerability, and their responsiveness to stimuli, cells are ideal candidates for therapeutic applications in many cases. Such promise is yet to be fully obtained as delivery of cells that functionally integrate with the desired tissues upon transplantation is still a topic of scientific research and development. Main known impediments for cell therapy include mechanical insults, cell viability, host's immune response, and lack of required nutrients for the transplanted cells. These challenges could be divided into three different steps: 1) Prior to, 2) during the and 3) after the transplantation procedure. In this review, we attempt to briefly summarize published approaches employing biomaterials to mitigate the above technical challenges. Biomaterials are offering an engineerable platform that could be tuned for different classes of cell transplantation to potentially enhance and lengthen the pharmacodynamics of cell therapies.

Nanomaterial surface modification toolkit: Principles, components, recipes, and applications

Surface-functionalized nanostructures are at the forefront of biotechnology, providing new opportunities for biosensors, drug delivery, therapy, and bioimaging applications. The modification of nanostructures significantly impacts the performance and success of various applications by enabling selective and precise targeting. This review elucidates widely practiced surface modification strategies, including click chemistry, cross-coupling, silanization, aldehyde linkers, active ester chemistry, maleimide chemistry, epoxy linkers, and other protein and DNA-based methodologies. We also delve into the application-focused landscape of the nano-bio interface, emphasizing four key domains: therapeutics, biosensing, environmental monitoring, and point-of-care technologies, by highlighting prominent studies. The insights presented herein pave the way for further innovations at the intersection of nanotechnology and biotechnology, providing a useful handbook for beginners and professionals. The review draws on various sources, including the latest research articles (2018-2023), to provide a comprehensive overview of the field.