Engineered regeneration最新文献

Micro-robots (MRs) are miniature machines with dimensions smaller than 1 mm and have semi- or fully-autonomous capabilities, including sensing, decision-making, and performing operations. These MRs have garnered significant attention in the precision medicine and personalized treatment field due to their ability to navigate narrow areas of the human body with non-desirable fluid flow. Specifically, MRs are actuated by a mechanism that generates propulsive force through the interaction between MRs' actuation modules and external energy sources in a specific direction. This driving mechanism enables the precise execution of medical treatment such as targeted drug delivery and minimally invasive surgeries. Nonetheless, MRs currently encounter certain challenges in clinical practice, including reliance on external energy sources, short lifespan, and difficulties in degradation or recovery within the human body. This article aims to review the common components and characteristics of driving mechanism for MRs' actuation modules, propose possible solutions to address current clinical challenges, and ultimately, explore the desirable structural and functional composition for the future development of MRs. Through these efforts, this review hopes to provide guidance for the future development of MRs in the field of precision medicine.

The extrusion-based bioprinting (EBBP) applications in the medical field tremendously increase due to its versatility in fabricating intricate geometry components with reasonable accuracy and precision. The bioink and its properties for an EBBP process are crucial in manufacturing parts with significant biocompatibility and functionality. The EBBP demands optimized parameters for obtaining good printability and cell viability. A better understanding of the various process parameters is essential for the researcher to optimize the mechanical and biological properties of the printed constructs. The biological, mechanical, and rheological parameters all together need to be evaluated to enhance the printability of tissue. This article concisely delineates the effect of the rheological and physiochemical parameters on the biological and mechanical properties of the printed tissues. The printing parameters and nozzle geometry, which considerably influence the printability, and shape fidelity of the bioprinted scaffolds are exemplified in detail. Additionally, the challenges and future aspects of enhancing printability are discussed succinctly.

Insulin secretion by pancreatic islets plays a vital role in regulating blood glucose levels. Nevertheless, the mechanism responsible for this dynamic insulin secretion has not been completely understood, particularly at the single islet level. In this study, we have successfully developed an easy microfluidic platform that allows for the exploration of dynamic glucose-stimulated insulin secretion (GSIS) at the single islet level. With the utilization of this platform, we evaluated dynamic GSIS from single islets isolated from both normal and diabetic rats. Our results demonstrate that islets can be categorized into three types based on their dynamic GSIS: Type I exhibits a biphasic GSIS profile with a fast first phase and flat second phase; Type II also has a biphasic GSIS profile with a fast first phase but a slow increased second phase; Type III displays only a slowly increased second phase and lacks a fast first phase. RNA sequencing analysis demonstrated that the cell type and exocytosis-specific genes are consistent with the proportion of cells and insulin release kinetics among the three types of islets, respectively. Moreover, our findings suggest that high expression of Atp5pb is anti-correlated with the first phase of insulin secretion. Furthermore, we revealed that diabetic islets exhibit only the type I GSIS response, indicating a deliberate impairment of the second phase of insulin secretion. Together, this device serves as a crucial tool in the research field of islets and diabetes, allowing researchers to investigate islet functional heterogeneity and identity at the single islet level.

Islet transplant has proven to be one promising strategy for diabetes treatment with minimal invasiveness, which restore the patient's endocrine function and avoid exogenous insulin injection. In the past decades, the ever-increasing diabetic population has brought more demand for this technology, therefore, accelerating the development of numerous engineering technologies optimizing the transplantation efficiency. In this review, we summarized the emerging engineering approaches in this field, aiming to provide a general understanding of islet transplantation challenges and the cutting edge of engineering technologies. Firstly, we introduced the islet product sources used for transplantation and analyzed their respective advantages and disadvantages. Afterwards, we focused on the advanced engineering strategies for maintaining islet graft viability and function in the transplantation. Finally, we summarized the engineering challenges and potential research directions in this field.

Sorting high-quality sperm with intact DNA, normal morphology, and active motility is crucial for clinically assisted reproductive technology, which influences the success of treatment and the health of offspring. Currently, microfluidic technology has been developed as a powerful platform for sperm sorting owing to its ability to manipulate fluid at the microscale and handle small samples. Specifically, microfluidic technology provides the necessary stimuli including fluid stimulus, chemical induction, and shape sift, which supports researchers in developing various sperm-sorting devices. According to the sorting principle, these devices can be divided into three categories: active sorting devices based on sperm rheological properties, passive sorting devices based on sperm physical properties, and external stimuli-induced sorting devices. Hence, we review a broad range of researches about sperm sorting with microfluidics and briefly present the properties of sperm and female reproductive tract to assist the design of microfluidic sperm sorting devices.

The development of neural tissue engineering has brought new hope to the treatment of spinal cord injury (SCI). Up to date, various scaffolds have been developed to induce the oriented growth and arrangement of nerves to facilitate the repair after injury. In this work, a conductive and anisotropic inverse opal substrate was presented by modifying polystyrene (PS) inverse opal films with carbon nanotubes and then stretching them to varying degrees. The film had good biocompatibility, and neural stem cells (NSCs) grown on the film displayed good orientation along the stretching direction. In addition, benefiting from the conductivity and anisotropy of the film, NSCs differentiated into neurons significantly. These results suggest that the conductive and anisotropic PS inverse opal substrates possess value in nerve tissue engineering regeneration.

Mineral ions play a crucial role in various biological processes in the human body, particularly in bone repair and regeneration. Supplementation with mineral ions offers several advantages over other therapies or treatments for bone repair and regeneration, such as higher biosafety, universal applicability, and compatibility with the immune system. Additionally, supplementation with mineral ions may avoid the need for invasive surgical procedures. The aim of this review is to provide a comprehensive overview of the functions of potentially beneficial mineral ions and their effects on bone regeneration and osteoporosis treatment. By examining previous studies, including in vitro cellular experiments, in vivo animal models, and clinical trials, this review compares the benefits and potential adverse effects of these mineral ions. Moreover, the review provides guidelines for suggested daily supplementation of these mineral ions to assist future preclinical and clinical studies in bone regeneration and osteoporosis treatment.

The dura mater is the outermost layer of meninges and consists of a dense elastic membrane that keeps cerebrospinal fluid inside the cavity. In most cranial surgical interventions, the dura mater is incised and needs to be repaired with a graft replacement. We assessed decellularized porcine dura mater as a novel graft material by quantifying the mechanical and structural properties of the dura membrane. Porcine dura mater was decellularized using the Sodium Dodecyl Sulfate (SDS) technique and subjected to uniaxial tensile testing, micro indentation testing, histological analysis, and Transmission Electron Microscopy (TEM). For native dura, we found the tensile modulus in the linear region (15%-25% strain) to be 19.31 ± 1.23 MPa, with an initial tensile modulus (0%-3.5% strain range) of 451 ± 0.30 kPa, and the failure stress as 4.61 ± 1.50 MPa at 35% strain. For decellularized dura, the tensile modulus in the linear region was 10.81 ± 0.88 MPa, the initial tensile modulus was 226 ± 22 kPa, and the failure stress was 4.55 ± 1.05 MPa at 55% strain. The effective compressive modulus was 7 to 19 kPa and 19–57 kPa for the native dura and the decellularized dura, respectively. Our histological and TEM observations showed that the orientation of fibers within the dura was maintained after decellularization. In short, our study demonstrated that decellularized porcine dura was able to maintain its overall morphological/structural integrity and preserve the native dura's mechanical behavior, which provides a solid foundation for its use as a functional grafting material.

Phantom limb is a disabling neuropsychiatric condition among amputees resulting in pain and disturbance that impact their functions, quality of life, and autonomy. While pharmacological approaches appeared to be ineffective, the emergence and integration of X-reality, including virtual reality, augmented reality, and mixed reality, might elevate the effectiveness of mirror therapy in managing phantom limb. The objective of this study is to review X-reality for managing phantom pain. A systematic search was conducted on PubMed, Scopus, Web of Science, PsycINFO, Embase, and CINAHL. Sixteen (n = 16) studies containing 66 lower-limb and 53 upper-limb amputees were included for the review over the thematic framework of amputee characteristics and intervention designs, while thirteen (n = 13) studies were further proceeded for the meta-analysis. We found eleven studies on virtual reality (n = 11), four studies on marker-based augmented reality (n = 4) and one study on mixed reality (n = 1) with a total of 40 game/task themes involving, motor skills, motor control, and stimulus-sensing. Regardless, all these interventions adopted the movement representation strategies with different techniques. Overall, the X-reality interventions reduced the pain level of the amputees (mean difference: -2.30, 95% CI, -3.38 to -1.22), especially the virtual reality subgroup (mean difference: -2.83, 95% CI, -4.43 to -1.22). However, there were substantial heterogeneity and partially explained by the subgroup analysis on publication year. The strength of evidence was limited by case reports and case series in this review.