Simvastatin-loaded 3D aerogel scaffolds promote bone regeneration.

BACKGROUND: It is imperative to design a suitable material for bone regeneration that emulates the microstructure and compositional framework of natural bone while mitigating the shortcomings of current repair materials. OBJECTIVE: The aim of the study is to synthesize a 3D aerogel scaffold composed of PLCL/gelatin electro-spun nanofiber loaded with Simvastatin and investigate its biocompatibility as well as its performance in cell proliferation and ossification differentiation. METHODS: PLCL/gelatin nanofibers were fabricated in coaxial electrospinning with simvastatin added. Fibers were fragmented, pipetted into molds, frozen, and dried. The morphology of fibers and contact angles in 4 groups of PLCL, PLCL@S, 3D-PLCL, and 3D-PLCL@S was observed and compared. MC3T3-E1 cells were planted at the four materials to observe cell growth status, and ALP and ARS tests were conducted to compare the ossification of cells. RESULTS: TEM scanning showed the coaxial fiber of the inner PLCL and outer gelatin. The mean diameter of the PLCL/gelatin fibers is 561 ± 95 nm and 631 ± 103 nm after the drug loading. SEM showed the fibers in the 3D-PLCL@S group were more curled and loose with more space interlaced. The contact angle in this group was 27.1°, the smallest one. Drug release test demonstrated that simvastatin concentration in the 3D-PLCL@S could remain at a relatively high level compared to the control group. The cell proliferation test showed that MC3T3-EI cells could embed into the scaffold deeply and exhibit higher viability in the 3D-PLCL@S group than other groups. The ossification tests of ALP and ARS also inferred that the 3D-PLCL@S scaffold could offer a better osteogenic differentiation matrix. CONCLUSION: The PLCL/gelatin aerogel scaffold, when loaded with Simvastatin, demonstrates a more pronounced potential in enhancing osteoblast proliferation and osteogenic differentiation. We hypothesize that this scaffold could serve as a promising material for addressing bone defects.

Application and research progress of 3D printing technology in biomedicine / 国际生物医学工程杂志

3D printing technology has unique advantages and broad application prospect in biomedicine field. In recent years, cell printing, tissue printing, and organ printing technologies h have appeared successively, and drug printing and medical device printing have been realized. For complex surgical cases, surgeons and researchers have explored a surgical program that involves 3D printing technology, and completed many clinical applications including case discussions, surgical simulations and implantation surgeries. These efforts promoted the application and development of 3D printing technology in medical field. The purpose of this paper is to describe the application and research status of 3D printing technology in medical field from the aspects of medical teaching, orthopedic surgery, stomatology, bioprinting, drug printing, medical device manufacturing, etc., and put forward the prospects for future development.

Algorithm for generating personalized external fixation model based on STL file / 国际生物医学工程杂志

Objective To study the generating algorithm of personalized external fixation model based on STL file, so as to realize the fabrication of personalized external fixation through 3D scanning, model generation and 3D printing. Compared with the traditional plaster fixation, the external fixation obtained by the proposed method has the advantages of good adhesion to the external surface of the limb, good gas permeability and light weight. Methods In order to generate a personalized external fixation model, the key generating algorithms of the model were studied. The point cloud file of the residual limb was obtained by a 3D scanner, and then was converted into an STL format file. The triangular patches were processed by cutting, offsetting, triangulating and hollowing to create an external fixation model with good gas permeability and conformable surface that is fully fitted with the body surface. Finally, the external fixation was fabricated by 3D printing. Results Using the improved point offset algorithm, the problem of severe distortion of the point offset at the plane and sharp corners was solved. Using the tangent sort method, the points on the contour ring were sorted clockwise to obtain a triangular profile. The hollowing of the model was achieved by using the typical three-dimensional "cutting tool" mathematical model and the STL file space intersection method. Conclusions The improved model generating algorithm was validated based on a wrist case, and the personalized external fixed fixation model with conformable surface was obtained. It is proved that the proposed model generating algorithm is effective and practical.

The design of plantar pressure distribution monitoring system and preliminary clinical application / 生物医学工程学杂志

Plantar pressure distribution can reflect the force of several key points on foot while standing and walking. A comprehensive understanding of the plantar pressure distribution makes great sense in the following aspects: the understanding of the normal foot biomechanics and function, clinical diagnosis, measurement of disease extent, postoperative efficacy evaluation, and rehabilitation research. A simple plantar pressure measurement device was designed in this study. This paper uses FlexiForce flexible sensor to pickup plantar pressure signal and USB A/D board to do data acquisition. The data are transferred into a laptop and processed by a VB-based software which can display, remember and replay the data. We chose patients with hallux valgus and normal people to measure the pressure distribution and make contrast analysis of plantar pressure with this device. It can be concluded that people with hallux valgus have higher pressure on the second metatarsophalangeal joint and the distribution move outward. The plantar pressure of patients postoperative could be greatly improved compared to the preoperative. The function of this device has been confirmed.

Research state and prospect of modelling physical human and its applications / 生物医学工程学杂志

Along with the development of computer technologies and digitization of human body's information, the digital human entered into a new stage of modelling physical features from the stage of reconstructing anatomical structures. By summarizing domestic and abroad relevant documents, we in this paper present the general scheme of digital human and the location of physical human as well as its conception and applied value. We especially analyze the modeling process of physical human, core technologies and its research and applications in four main fields: electromagnetic radiation, ultrasound propagation, bioimpedance measurements and biomechanical analysis. We also analyze and summarize existing problems of present physical human model and point out the future development trends of physical human.

Research progress of methods for brain vigilance improvement / 生物医学工程学杂志

Vigilance is defined as the ability to maintain attention or alertness over prolonged periods of time. Since Mid-20th century, following the increasing man-machine communication, high level of vigilance has been demanded in many areas including driving safety, medical care and therapy, aerospace and military affairs, etc. Therefore, finding quick methods to improve the level of vigilance has become a key issue in medical study. Based on physical regulation, chemical regulation and physiological regulation, the research progress has been summarized in this paper. We, furthermore, also try to predict the future trend in this academic area and develop some tentative ideas about seeking more effective and convenient ways to improve the level of brain vigilance.

The development of techniques for liquid level detection in auto clinical laboratory analyzers / 生物医学工程学杂志

Liquid level detection (LLD) is necessary for eliminating carry-over of needle's outside by limiting the depth the needle probes into liquid in auto clinical laboratory analyzers. This paper listed various demands of liquid-handling system under different situations; reviewed various LLD techniques, such as capacitive, air pressure, mechanical vibration, ultrasound, light reflection, CCD imaging etc.; briefly introduced the working principles, features, and limitation of the LLDs; and recapitulated the characteristics of contact and non-contact LLDs. Lastly, the next generation technique of LLD is prospected.