Session Detail

I present the mechanical structure analysis of the transition metal oxide hollow microsphere by BME. The Uniaxial com-pressive stress-strain curves can be presented by elstomeric foam model. In this study, hollow mineral microspheres of tungsten, molybdenum and iron oxides were prepared by bacterial mineral excretion (BME), and the uniaxial compres-sive strain-stress curve of these hollow microsphere shells was measured and analyzed by the elastomeric foam model.

 

Peripheral nerve injuries (PNI) is a common clinical challenge and issue to human health that arise from industrial injuries, natural disasters, war wounds, motor vehicle accidents, tumor damage and even some systemic diseases result in complete loss of motor functionality and paralysis. Approximately 2–5% of trauma patients experience a PNI and about 500,000 surgical procedures are carried out each year in the America. In the Europe alone, more than 300,000 PNI cases per year and esti-mated that more than 5 million cases of PNI occur annually worldwide due to traumatic events. Here, we developed an elastic 3D printed conduit fabricated by digital light processing (DLP)-type additive manufacturing for nerve regeneration. In 3D printing technologies, we can fabricate various scaffold in any length as well as diameter and overcome the geometries from individual differences according to individual patients. Especially, unique pattern inside the conduit could also be easily designed. Besides, mesoporous silica/graphene oxide nanoparticles (PSGO NPs) provide the large cargo to deliver growth factor and some specific protein for nerve regeneration. By means of 3D-printing process, we could prepare gradient concentration of PSGO NPs inside for guiding nerve growth. PSGO NPs also generated microcurrent to aid sciatica regeneration under high frequency magnetic field (MFMF). Nerve would grow along the micro-groove and gradient concentration of PSGO NPs in the lumen of the guide we designed in vitro and in vivo test. Over 1 month, Sprague-Dawley (SD) rats successfully regenerated across a 5 mm nerve gap and resulted in functional return.

 

This study aims to investigate the role of alkyl chain length of monothiol-terminated alkyl carboxylic acids in the synthesis, characterization, and application of gelatin-g-poly(N-isopropylacrylamide) (GN) biodegradable in situ gelling carriers for antiglaucoma drug delivery. The study showed that with increasing alkyl chain length, the hydrophobicity of thermoresponsive polymer segments significantly increased. In addition, the greater hydrophobic association favored the decrease in both phase transition temperature and weight loss of GN copolymers, thereby accelerating their temperature-triggered gelation process and retarding the degradation progress under physiological conditions. The benefits from these features allowed the pilocarpine carriers to increase drug payload and extend drug release. Results of clinical observations and histological examinations demonstrated that the therapeutic efficacies in treating glaucomatous damage are in response to in vivo drug release profiles from various intracamerally injected GN carriers. The research findings suggest the influence of alkyl chain length of chain transfer agent-mediated polymer hydrophobicity and degradability on pharmacological bioavailability and action of pilocarpine in a glaucomatous rabbit model.

 

The autograft is the current “gold standard” for the nerve regeneration. However, the functional results of using an auto-graft are unstable and the lack of a donor nerve also retards the application of the autograft in a clinical setting. Conse-quently, it is highly desirable to develop engineered alternatives to the autografts with design flexibility and improved perfor-mance. In this study, we using Digital light processing (DLP) technology in 3D printing to developed a photopolymerizable water-based polyurethane (PU) material. In vitro the MTT assay and immunofluorescent display Wharton's jelly mesen-chymal stem cell has good bio-compatibilty on PU. Animal experiment show the 3D printing conduit load Schwann cell spheroids dramatically increased the nerve regeneration rate. This study demonstrates the potential of 3D-printing PU nerve conduit for potential clinical applications in the future.

 

Stimuli-responsive polymeric nanoparticles have been utilized as effective vehicles for escorting chemotherapeutic agents with optimal therapeutic effect. However, solid tumor microenvironment restrains deep drugs transportation due to its dense extracellular matrix, irregular vascular network and high interstitial fluid pressure. Therefore, the objective of this study is to develop reductive and enzyme sensitive polypeptide-based nanoparticles with programmable degradation manner for solid tumor treatment. The backbone of copolymers is composed of polyCys, polyHis and polyLeu blocks which exhibited a reversible disulfide bond protective layer, proton sponge effect and hydrophilic domain, respectively. Vismodegib, a hedgehog signal pathway inhibitor, was complexed in the core of the nanoparticles to show synergistic effect with anti-cancer drug, doxorubicin. From NMR and FTIR spectra, the mPEG and doxorubicin were successfully conjugated onto the polypeptide sequence through chemical reactions, respectively. The nanoparticles self-assembled into spherical shape through sonication with a size around 220 nm. Also, the programmable dissociation process could be clearly seen from the TEM images. In in vitro cell culture model, the nanoparticle decorated with active targeting ligand, tLyP-1, performed high selectivity toward the expression of neuropilin-1 (NRP-1) receptor on breast cancer cells. Moreover, in tumor spheroid 3D model, the nanoparticles exerted desirable therapeutics on collapsing ECM matrix and anticancer effect. These nanocarriers are expected to process through adverse ECM barrier with multiple endogenous stimuli-responsive properties and exert a safe and precise delivery. This tailored-designed vehicle has potential in treating NRP-1 over-expressed solid tumor and diseases with intense fibrosis problem.

 

At present, one out of every five people in Taiwan suffers from articular cartilage disease. The structure and function of cartilage can't be fully restored by using medical treat-ment or artificial joint surgery. The continuous development and research of tissue engineering can improve the regeneration ability and complete repair of cartilage tissue. In this study, tissue engineering and three dimensional (3D) printing technology were used to develop hyaluronic acid (HA)/polyurethane (PU) light cured cartilage composite scaffolds for cartilage tissue engineering. Hyaluronic acid is an extracellular component of articular cartilage that binds aggrecan to macromolecular proteoglycans and acts as a lubricant in cartilage fluid. Other studies have indicated that hyaluronic acid has the tendency to induce mesenchymal stem cells (MSCs) to differentiate into chondrocytes and form supportive cell differentiation, and also binds to the composition of other proteins and extracellular matrices, and is therefore often used as a natural material. Hyaluronic acid modified or chemically reacted with different chemical properties may have a good effect on its biological activity. Therefore, development of different modified hyaluronic acid will enhance the repair and regeneration of cartilage tissue. The results of this study show that the HA/waterborne PU light cured materials with special modification are applied to the digital light processing (DLP) 3D printing technology with excellent operability and printability. The cartilage scaffolds can be fabricated with complex porous structure and also has good performance and biocompatibility. This study will help the development of the cartilage disease therapy and precision medicine.