jen-chang Yang

Taipei Medical University | TMU · College of Biomedical Engineering

Aim To investigate the efficacy of nanodiamond irrigation solution with sonic agitation for removing of hard‐tissue debris (HTD) within the isthmus‐containing mesial roots of human mandibular molars using micro‐CT analysis. Methodology Forty mesial roots of extracted human mandibular molars were selected based on micro‐computed tomography scans (9...

Platelet extracellular vesicles (pEVs) isolated from clinical‐grade human platelet concentrates are attracting attention as a promising agent for wound healing therapies. Although pEVs have shown potential for skin regeneration, their incorporation into wound bandages has remained limitedly explored. Herein, gelatine‐based hydrogel (PAH‐G) foams fo...

In the present work, iron–sillenite (Bi25FeO40) was synthesized using a simple solid-state reaction method and characterized. The effects of the synthesis conditions on the phase purity of Bi2O3/Fe3O4, morphological features, and possible application as an XRD/MRI dual-contrast agent were investigated. For the synthesis, the stoichiometric amounts...

Progesterone (P4) plays a pivotal role in regulating the cancer progression of various types, including breast cancer, primarily through its interaction with the P4 receptor (PR). In PR-negative breast cancer cells, P4 appears to function in mediating cancer progression, such as cell growth. However, the mechanisms underlying the roles of P4 in PR-...

Impaired wound healing is a significant complication of diabetes. Platelet-derived extracellular vesicles (pEVs), rich in growth factors and cytokines, show promise as a powerful biotherapy to modulate cellular proliferation, angiogenesis, immunomodulation, and inflammation. For practical home-based wound therapy, however, pEVs should be incorporat...

Background/purpose The chemo-mechanical caries-removal technique is known to offer advantages of selective dentin caries treatment while leaving healthy dental tissues intact. However, current sodium hypochlorite based reagents usually excessively damage dentin collagen. Therefore, the purpose of this study was to develop a novel chemo-mechanical c...

Sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are commonly recommended for effectively removing organic and inorganic components in the smear layer. This layer is found on root canal walls after root canal instrumentation. However, high-concentration EDTA reduces the strength of dentin and the dissolution efficacy of organi...

In this study, the effects of sodium lauryl sulfate and various amino acids (DL-aspartic acid, dodecanedioic acid, and suberic acid) on the formation of calcium-deficient hydroxyapatite via hydrolysis of α-tricalcium phosphate (α-TCP) were investigated; moreover, a combined effect of these additives and ethylene glycol as a synthesis medium was als...

Magnesium whitlockite (Mg-WH, Ca18Mg2(HPO4)2(PO4)12) is a promising candidate for biomedical application in bone regeneration; however, the fabrication of Mg-WH bioceramics by conventional methods is limited. Mg-WH is known to be...

Polypropylene (PP), a promising engineering thermoplastic, possesses the advantages of light weight, chemical resistance, and flexible processability, yet preserving insulative properties. For the rising demand for cost-effective electronic devices and system hardware protections, these applications require the proper conductive properties of PP, w...

Polyetherketoneketone (PEKK) is an alternative material for use in removable partial denture frameworks; these frameworks must exhibit antibacterial properties to reduce the risk of periodontal disease. In the present study, silver nanoparticles (AgNPs) were synthesized via the reduction of silver nitrate with sodium borohydride in a solution conta...

Thymoquinone (TQ) is an antioxidant, anti-inflammatory, and hepatoprotective compound obtained from the black seed oil of Nigella sativa . However, high hydrophobicity, instability at higher pH levels, photosensitivity, and low oral bioavailability hinder its delivery to the target tissues. A self-nanoemulsifying drug delivery system (SNEDDS) was f...

The wet chemistry route has been developed to prepare calcium hydroxyapatite (Ca10(PO4)6(OH)2, (HA)) thin films on a silicon substrate using the novel low-temperature sol-gel and dissolution-precipitation approach. The calcium carbonate thin films on the silicon substrate were obtained by spin-coating technique when substrates were repeatedly coate...

Hydroxyapatite Ca10(OH)2(PO4)6 is a well-known efficient adsorbent of dyes, heavy metal ions, and radionuclides. Its adsorption efficacy strongly depends on crystalline/amorphous structure, defectiveness, texture characteristics, and morphology. Herein, we synthesized Mg²⁺-, Sr²⁺-, and Fe³⁺-substituted (5 mol%) amorphous calcium phosphates as an ef...

Many revolutionary approaches are on the way pertaining to the high occurrence of tooth decay, which is an enduring challenge in the field of preventive dentistry. However, an ideal dental care material has yet to be fully developed. With this aim, this research reports a dramatic enhancement in the rehardening potential of surface-etched enamels t...

We presented an approach to address cancer cell chemotaxis and response to tyrosine kinase inhibitor PD153035 at the single-cell level. We applied an optical tweezer system together with the platform at the single-cell level to manipulate an epidermal growth factor (EGF)-coated bead positioned close to the filopodia to locally stimulate HT29 cells,...

The current work focuses on the development of a novel electrospun silk fibroin (SF) nonwoven mat as a GTR membrane with antibacterial, biomineralization and biocompatible properties. The γ-poly glutamic acid (γ-PGA)-capped nano silver fluoride (NSF) and silver diamine fluoride (SDF) were first synthesized, which were dip-coated onto electrospun si...

Mineral trioxide aggregate (MTA) is well known as an effective root canal filling material for endodontics therapy. Within MTA, bismuth oxide (Bi2O3) serving as the radiopacifier still has biocompatibility concerns due to its mild cytotoxicity. In the present study, we tried to modify the Bi2O3 radiopacifier by doping hafnium ions via the sol-gel p...

This study aims to fabricate silk fibroin/calcium sulfate (SF/CS) composites by one-pot synthesis for bone regeneration applications. The SF was harvested from degummed silkworm cocoons, dissolved in a solvent system comprising of calcium chloride:ethanol:water (1:2:8), and then mixed with a stoichiometric amount of sodium sulfate to prepare variou...

Selective laser melting (SLM) is extensively used for fabricating metallic biomedical products. After 3D printing, it is almost always advisable to apply a heat treatment to release the internal tensions or optimize the mechanical properties of the printed parts. The aim of this paper is to investigate the effects of heat treatment of SLM printed T...

In the present work, effect of Mn doping on hydrolysis rate of low-temperature synthesized metastable α-tricalcium phosphate (α-TCP) was investigated. α-TCP powders containing different amount of Mn²⁺ ions (0, 0.5 and 1 mol%) were synthesized by wet co-precipitation process, followed by annealing and crystallization of as-precipitated amorphous cal...

This Scientific Report 2020-2021 presents the main research activities carried out by the Professors and research teams of the College of Biomedical Engineering at Taipei Medical University, Taipei, Taiwan. The report highlights the main research focus of the College in the fields of (a) Biomedical Materials and Tissue Engineering, (b) Nanomedicine...

The objective of this study was to verify the feasibility of electrolyzed oxidizing (EO) water as a mouthwash through the evaluation of its in vivo toxicity by embryonic zebrafish and antimicrobial efficacy against Streptococcus mutans (S. mutans). Methodology: Each 1.5-3.0 g of sodium chloride (NaCl), sodium bromide (NaBr), or calcium chloride (...

Background/Purpose Mineral trioxide aggregate (MTA) was widely used in endodontic therapy as bioceramic material. Although MTA has high biocompatibility, it may lead to tooth discoloration. The aim of this study was to investigate the discoloration of two different bioceramic materials and the effects of internal bleaching. Methods Thirty single-c...

The superlative mechanical properties of spider silk and its conspicuous variations have instigated significant interest over the past few years. However, current attempts to synthetically spin spider silk fibers often yield an inferior physical performance, owing to the improper molecular interactions of silk proteins. Considering this, herein, a...

Mineral trioxide aggregate (MTA) is widely used in various dental endodontic applications such as root-end filling, furcal perforation repair, and vital pulp therapy. In spite of many attempts to improve handling properties and reduce the discoloration of MTA, the ideal root canal filling material has yet to be fully developed. The objective of thi...

In the present work, Fe³⁺ and Zn²⁺ co-substituted β-tricalcium phosphate (β-TCP) has been synthesized by wet co-precipitation method. Co-substitution level in the range from 1 to 5 mol% has been studied. Thermal decomposition of as-prepared precipitates was shown to be affected by introducing of foreign ions, decreasing the decomposition temperatur...

Pore size and connectivity of artificial bone scaffolds play key role in regulating cell ingrowth and vascularization during healing. The objective of this study was to develop a novel process for preparing 3D pore-interconnected open-cell bone substitutes with varying pore sizes. This was achieved by thermal-induced expansion, drying, then sinteri...

The objective of this study was to evaluate the antibacterial efficacy against Enterococcus faecalis and Streptococcus mutans and in vivo toxicity using embryonic zebrafish assays of sodium hypochlorite (NaOCl) and electrolyzed oxidizing (EO) water (containing hypochlorous acid (HOCl))-based root canal irrigating solutions. Methodology: Using 100...

The objective of this study is to investigate the synergistic effects of acid etching and metal-ion chelation in dental smear layer removal using wasted Ganoderma tsugae derived chitosans. The wasted Ganoderma tsugae fruiting body was used to prepare both acid-soluble fungal chitosan (FCS) and alkali-soluble polysaccharide (ASP). To explore the eff...

Due to increasing global warming resulting from the greenhouse effect, subsequent environmental impacts and corresponding ecological influences are unavoidable. These problems are becoming more serious with time. Due to rising temperatures, the survival crisis of polar bears is a very often reported issue, because polar bears are encountering short...

The guided tissue regeneration (GTR) membrane is a barrier intended to maintain a space for alveolar bone and periodontal ligament tissue regeneration but prevent the migration of fast-growing soft tissue into the defect sites. This study evaluated the physical properties, in vivo animal study, and clinical efficacy of hydrophilic PLA95/β-TCP GTR m...

This document presents the Research fields and performance of the College of Biomedical Engineering of Taipei Medical University (TMU). After only three years of existence, our College of Biomedical Engineering (CBME) was already listed in the top 150 in Academic Ranking of World Universities (ARWU) in 2018. CBME has 26 full-time professors and clo...

According to the Times Higher Education (THE) Asia University Ranking 2018, Taipei Medical University continues to improve its ranking to reach now the 83th place. Our College of Biomedical Engineering was for the first time listed in the top 150-200 biomedical engineering academic institutes in the world in the ARWU ranking, after only 3 years of...

In spite of all the efforts towards deciphering the silk spinning process of spiders, the underlying mechanism is yet to be fully revealed. In this research, we designed a novel approach that allowed us to quantitatively evaluate the concentration change of silk dope during the liquid-to-solid spinning process of the orb-weaver Nephila pilipes. As...

Bismuth oxide (Bi2O3) is an effective additive used to enhance radiography resolution for dental materials. However, there are potential concerns regarding its biocompatibility and connection to tissue discoloration. In the present study, we modified the radiopacity properties of Bi2O3 with zirconium oxide (ZrO2) using a sol-gel process and investi...

There are exciting research topics at the College of Biomedical Engineering of Taipei Medical University for Foreign MS and PhD students.We have several international MS and PhD programs in Biomedical Engineering covering Biomedical Materials and Tissue Engineering, Nanotechnologies and Medical Engineering, and Bio-Optomechatronics. Teaching is 100...

In this study, Bi2O3 powders were modified into ZrO2-doped Bi2O3 powders by adding zirconium oxide through precipitation processes. The radiopacity and physical properties of as-synthesized and heat-treated products were investigated. The products were primarily composed of a mixture of β-Bi7.38Zr0.62O12.31 and α-Bi2O3 obtained below 700 °C, then t...

The primary success of implantation is according to osseointegration. The bone-to-implant contact (BIC) % is one of the methods to evaluate the osseointergation. In our study, the mini-pig animal model was used to study the osseointegration in different implant macro-design in early implantation period. Eight mini-pigs were divided into 2 groups an...

The objective of this study was to evaluate osseointegration of surface-treated zirconia dental implants using a mini-pig model. Experimentally, zirconia implants with acid-etched surfaces and commercial titanium implants as a control group were introduced into the maxilla and mandible of nine mini-pigs. After 8 and 16 weeks, animals were sacrifice...

Poly(lactic acids) (PLAs) with different molecular weights (MWs) were prepared by autoclaving a commercial PLA for different time periods. The harvested PLAs were characterized by different techniques. Gel permeation chromatography results showed that the MW of PLA decreased with increasing autoclaving time. The Mark–Houwink parameters for PLA in d...

Introduction: The objective of this in vitro study is to evaluate the effective and long-term occlusion of dentinal tubules using a novel calcium lactate phosphate (CLP) based desensitizing agent. Methods: Dentin disks (n = 9) were pre-etched using 1 M lactic acid for 30 s and individually treated with Colgate(®) Pro-Relief™ paste, CLP paste, an...

The invention provides an anion-containing calcium phosphate compound, composition and dental patch comprising the same and their use in remineralizing teeth. The anion-containing calcium phosphate compound has the following formula: (Ca+2)x(anion−a)y(PO4 −3)z wherein 2x=(a*y+3z); a is an integer of 1 to 3; and each of x, y and z is not 0.

Cover Legend The cover image, by William Bentley et al., is based on the Article Conferring biological activity to native spider silk: A biofunctionalized protein-based microfiber, DOI: 10.1002/bit.26065.

Spider silk is an extraordinary material with physical properties comparable to the best scaffolding/structural materials, and as a fiber it can be manipulated with ease into a variety of configurations. Our work here demonstrates that natural spider silk fibers can also be used to organize biological components on and in devices through rapid and...

Photodynamic inactivation (PDI) combined with chitosan has been shown as a promising antimicrobial approach. The purpose of this study was to develop a chitosan hydrogel containing hydroxypropyl methylcellulose (HPMC), chitosan and toluidine blue O (TBO) to improve the bactericidal efficacy for topical application in clinics. The PDI efficacy of hy...

The common methods for synthesizing calcium phosphates include solid-state reaction, hydrothermal, sol–gel, and wet precipitation. The purpose of this study was to prepare various calcium phosphate bioceramics through a continuous reactor equipped with a static mixer. The precursors, amorphous calcium phosphate (ACP), and poor crystal hydroxyapatit...

Bioceramic is a kind of material which emits nonionizing radiation and luminescence, induced by visible light. Bioceramic also facilitates the breakup of large clusters of water molecules by weakening hydrogen bonds. Hydrogen bond weakening, which allows water molecules to act in diverse ways under different conditions, is one of the key mechanisms...

The purpose of this in vivo study was to evaluate the effect of human dental pulp stem cells (hDPSCs) on various resorbable calcium sulfate/calcium phosphate bone grafts in bone regeneration. Granular particles of calcium sulfate dehydrate (CSD), α-calcium sulfate hemihydrate/amorphous calcium phosphate (α-CSH/ACP), and CSD/β-tricalcium phosphates...

The invention relates to a method of preparing a composite or porous composite used as a biodegradable scaffold, the composite prepared therefrom and the use of the composite. In particular, the composite is a calcium sulfate-polylactic acid composite or porous composite and the composite can be especially used as an in situ pore forming scaffold.

A method of surface treatment for zirconium oxide implants and the etching formula for the same are disclosed. The processes are carried out at room temperature. The average surface roughness Ra and the standard deviation of the implant are measured showing significant improvement while comparing with the un-treated sample and the hydrofluoric acid...

This study presents synthesis and characterization of calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp) and whitlockite (Ca18Mg2H2(PO4)14) composite obtained from dairy product. First, calcium containing powders were precipitated from whey permeate by combining the effect of alkaline pH and temperature. Subsequently a calcium containing phase was coll...

Background/purpose The aim of this study was to investigate whether storage of extracted teeth in transportation solution for 24 hours has a negative effect on the cell density and mechanical properties of thawed pulp tissue extracted from frozen intact teeth. Material and methods Human premolars were kept in transportation solution for 0 hours or...

Objective: The objective of this in vitro study was to evaluate the rehardening potential of a nano-hydroxyapatite/gamma-polyglutamic acid (nano-HAp/γ-PGA) on surface-etched enamels. Method: Thirty-two coronal-part of human premolars were selected and divided into four groups (N=8). Artificial surface-etched specimens were treated by 1M acetic ac...

Previous synthesis routes created apatites in low crystallinity and high crystallinity states, but a wider range will extend the design capabilities of apatites for hard tissue replacements. While high crystallinity apatites are more conventional, this work investigated lower crystallinity variations from an amorphous state to low crystallinity apa...

Novel poly-L-lactic acid (PLLA) microtube array membranes (MTAMs) with a porous wall structure were prepared by electrospinning. Porogen of polyethylene glycol (PEG) was mixed with PLLA and dissolved in a dichloromethane/dimethylformamide solvent. The solution dope was delivered to the outer layer of coaxial spinneret, while the PEG/polyethylene ox...

This objective of this study is to investigate the antibacterial properties and biocompatibility of Portland cement/bismuth oxide/ zinc oxide (PC/Bi2O3/ZnO) composites hydrated by a novel calcium lactate gluconate (CLG) accelerant. The 23.1 wt% CLG aqueous solution and deionized water (DDW) were used to set PC/Bi2O3/ZnO, MTA (mineral trioxide aggre...

This study evaluates the radiopacity and cytotoxicity of Portland cements containing a radiopacifier of bismuth oxide (Bi2O3) with yttria-stabilized zirconia (YSZ) dopant. Various radiopacifier powders of Bi2O3 with 0%, 15%, 30%, and 100% YSZ dopant were prepared by solid-state reaction at 700°C for 12 hours and characterized by x-ray diffraction....

Previous synthesis routes created apatites in low crystallinity and high crystallinity states, but a wider range will extend the design capabilities of apatites for hard tissue replacements. While high crystallinity apatites are more conventional, this work investigated lower crystallinity variations from an amorphous state to low crystallinity apa...

The objective of this research is to study the e®ects of alumina addition on the microstructure-mechanical property relationship and sintering behavior of yttria (3 mol%)-stabilized zirconia (YSZ) ceramics. Well-dispersed YSZ/Al 2 O 3 ceramics containing 10À40 wt.% Al 2 O 3 were prepared by solid state reaction method. The relative density, average...

Calcium phosphate cement (CPC) is a promising material for use in minimally invasive surgery for bone defect repairs due to its bone-like apatitic final setting product, biocompatibility, bioactivity, self-setting characteristics, low setting temperature, adequate stiffness, and easy shaping into complicated geometrics. However, even though CPC is...

Photodynamic therapy (PDT), utilizing photosensitizers and light, has received considerable interests for its potential to treat microbial infections. The advantages of antimicrobial PDT include a broad spectrum of action, efficient killing against wild-type as well as drug-resistant pathogens. Therefore, antimicrobial PDT could be a valuable tool...

Typical electrospun polylactic acid (PLA) membranes revealing potential hydrophobicity and inflammation from acid release during degradation are major drawbacks as an ideal guided tissue regeneration (GTR) barrier. This study investigated the in vitro degradation properties of electrospun PLA/beta-tricalcium phosphate (β-TCP) membranes treated by p...

Objective: Mineral trioxide aggregate (MTA) has been used as a dental filling material since 1993. It is a good choice for root end filling, pulp capping and pulpotomy dressing materials. Poor handling properties and long setting time of MTA limit its application in dental clinics. Adding additives into MTA to modify its properties may expand the p...