Publications by authors named "Joo Ong"

Endotracheal Tubes (ETTs) maintain and secure a patent airway; however, prolonged intubation often results in unintended injury to the mucosal epithelium and inflammatory sequelae which complicate recovery. ETT design and materials used have yet to adapt to address intubation associated complications. In this study, a composite coating of electrospun polycaprolactone (PCL) fibers embedded in a four-arm polyethylene glycol acrylate matrix (4APEGA) is developed to transform the ETT from a mechanical device to a dual-purpose device capable of delivering multiple therapeutics while preserving coating integrity.

View Article and Find Full Text PDF

It is known that titanium (Ti) implant surfaces exhibit poor antibacterial properties and osteogenesis. In this study, chitosan particles loaded with aspirin, amoxicillin or aspirin + amoxicillin were synthesized and coated onto implant surfaces. In addition to analysing the surface characteristics of the modified Ti surfaces, the effects of the modified Ti surfaces on the adhesion and viability of rat bone marrow-derived stem cells (rBMSCs) were evaluated.

View Article and Find Full Text PDF

Regenerating large bone defects requires a multifaceted approach combining optimal scaffold designs with appropriate growth factor delivery. Supraphysiological doses of recombinant human bone morphogenetic protein 2 (rhBMP2), typically used for the regeneration of large bone defects clinically in conjunction with an acellular collagen sponge (ACS), have resulted in many complications. In this study, we develop a hydroxyapatite/collagen I (HA/Col) scaffold to improve the mechanical properties of the HA scaffolds, while maintaining open connected porosity.

View Article and Find Full Text PDF

Beta-tricalcium phosphate (β-TCP)-based bioinks were developed to support direct-ink 3D printing-based manufacturing of macroporous scaffolds. Binding of the gelatin:β-TCP ink compositions was optimized by adding carboxymethylcellulose (CMC) to maximize the β-TCP content while maintaining printability. Post-sintering, the gelatin:β-TCP:CMC inks resulted in uniform grain size, uniform shrinkage of the printed structure, and included microporosity within the ceramic.

View Article and Find Full Text PDF

Ti-9Mn and Ti-15Mn were prepared using an arc furnace in order to understand their osteogenic behavior as a biomedical implant. Ti-9Mn surface showed a significantly lower contact angle value (41%) as compared with the Ti-15Mn surface. The higher Ra and lower hydrophilicity values of Ti-9Mn alloy as compared with Ti-15Mn alloy indicates that Ti-9Mn can have better osteoconductive properties.

View Article and Find Full Text PDF

Electrical stimulus-responsive drug delivery from conducting polymers such as polypyrrole (PPy) has been limited by lack of versatile polymerization techniques and limitations in drug-loading strategies. In the present study, we report an chemical polymerization technique for incorporation of biotin, as the doping agent, to establish electrosensitive drug release from PPy-coated substrates. Aligned electrospun polyvinylidene fluoride (PVDF) fibers were used as a substrate for the PPy-coating and basic fibroblast growth factor and nerve growth factor were the model growth factors demonstrated for potential applications in musculoskeletal tissue regeneration.

View Article and Find Full Text PDF

Background: Volumetric tissue-engineered constructs are limited in development due to the dependence on well-formed vascular networks. Scaffold pore size and the mechanical properties of the matrix dictates cell attachment, proliferation and successive tissue morphogenesis. We hypothesize scaffold pore architecture also controls stromal-vessel interactions during morphogenesis.

View Article and Find Full Text PDF

Objectives/hypothesis: Novel laryngotracheal wound coverage devices are limited by complex anatomy, smooth surfaces, and dynamic pressure changes and airflow during breathing. We hypothesize that a bioinspired mucoadhesive patch mimicking how geckos climb smooth surfaces will permit sutureless wound coverage and also allow drug delivery.

Study Design: ex-vivo.

View Article and Find Full Text PDF

Extracellular matrix (ECM) products have the potential to improve cellular attachment and promote tissue-specific development by mimicking the native cellular niche. In this study, the therapeutic efficacy of an ECM substratum produced by bone marrow stem cells (BM-MSCs) to promote bone regeneration in vitro and in vivo were evaluated. Fluorescence-activated cell sorting analysis and phenotypic expression were employed to characterize the in vitro BM-MSC response to bone marrow specific ECM (BM-ECM).

View Article and Find Full Text PDF

Study Design: Clinical audit via retrospective review of a database.

Purpose: To report an early experience using ultrasound-guided lumbar spinal injection for axial and radicular pain in an Asian multiethnic cohort.

Overview Of Literature: Ultrasound-guided spine injection therapy is a comparatively new technique in the management of axial and radicular pain from degenerative lumbar spinal conditions, which may be a reasonable alternative to conventional fluoroscopic or computed tomography-guided injection.

View Article and Find Full Text PDF
Article Synopsis
  • - Many women worry about their milk supply, which often leads to breastfeeding challenges or early weaning; factors like maternal health, infant latch, and feeding frequency significantly influence milk production and should be addressed first.
  • - Oral galactagogues, substances that promote milk production, can be either pharmacological or natural; their selection depends on cultural familiarity and preferences regarding their use.
  • - The study aims to evaluate the effectiveness of oral galactagogues on increasing milk production among breastfeeding mothers with healthy term infants, relying on randomized controlled trials for evidence.
View Article and Find Full Text PDF

Purpose: This study evaluated a novel injectable, self-setting, osteoconductive, resorbable adhesive that provides immediate implant stabilization.

Materials And Methods: Twenty-six large canines had the mandibular second through fourth premolars and the first molar removed bilaterally. After 3 months, oversized osteotomies were prepared with only the apical 2 mm of the implant engaging native bone.

View Article and Find Full Text PDF

Background: Little is known regarding the interaction of dental implant surface nanotubes and oral soft and hard tissues. The purpose of this study was to evaluate both histologically and radiographically the qualitative and quantitative effects of dental implant surface nanotubes on hard and soft tissue in a canine model.

Methods: Three subgroups consisting of a combination of test and control implants and abutments (Group A: control implant/control abutment, Group B: control implant/test abutment: Group C: test implant/test abutment) were placed in edentulous mandibles of six large-breed canines.

View Article and Find Full Text PDF

Critically sized bone defects are often compounded by infectious complications. The standard of care consists of bone autografts with systemic antibiotics. These injuries and treatments lead to donor site morbidity, antibiotic resistant strains of bacteria, and often end stage amputation.

View Article and Find Full Text PDF

This article reports for the first time our successful result in the synthesis of antibacterial single-phase newberyite (NB, MgHPO .3H O), an important magnesium phosphate (MgP) bioceramic. The prime novelty lies in the fact that we explore novel MgPs as next-generation orthopedic biomaterials as opposed to conventional calcium phosphates (CaP).

View Article and Find Full Text PDF

Polymer network structures in the design of bilayer hydrogels for oral drug delivery systems contribute to the mechanical stability as well as the stimulus responsive drug release. We report a strategy to improve the stability of polyelectrolyte layer interfaces in bilayer hydrogels by employing concepts from tough interpenetrating hydrogel network design. Polyvinyl alcohol as the neutral substrate and Polyacrylic acid as the pH-sensitive layer were used to prepare bilayers capable of pH-sensitive bending behavior, and inverse double network structures were compared to conventional thin film coated bilayers in this study.

View Article and Find Full Text PDF

Transplantation of primary hepatocytes has been used in treatments for various liver pathologies and end-stage liver disease. However, shortage of donor tissue and the inability of hepatocyte proliferation in vitro have lead to alternative methods such as stem cell-derived hepatocyte-like cells (HLCs). Mesenchymal stromal/stem cells, and amniotic epithelial cells were isolated from human bone marrow (BM-MSCs), lipoaspirates (ASCs), and amniotic tissue (AECs) respectively.

View Article and Find Full Text PDF

Purpose: The study and development of antibacterial materials for use in dental applications is growing with the development of novel materials and procedures. Examination of the effects of such antibacterial materials on oral pathogens as well as on stability and longevity of dental restorations is of paramount importance to the field.

Results: This review addressed the range of topics covered by the manuscripts presented at the Seoul symposium on antibacterial dental materials.

View Article and Find Full Text PDF

Biologic substrates, prepared by decellularizing and solubilizing tissues, have been of great interest in the tissue engineering field because of the preservation of complex biochemical constituents found in the native extracellular matrix (ECM). The integrity of the ECM is critical for cell behavior, adhesion, migration, differentiation, and proliferation that in turn affect homeostasis and tissue regeneration. Previous studies have shown that various processing methods have a distinctive way of affecting the composition of the decellularized ECM.

View Article and Find Full Text PDF

Introduction: Sports concussion remains challenging to manage despite changes to policy and practice since the 2012 International Consensus Conference on Concussion in Sport. Emergency physicians (EPs) are usually the first line of medical care for athletes in amateur and youth collision sports. This single-centre cross-sectional study aimed to establish EPs' understanding and management of concussion in Singapore.

View Article and Find Full Text PDF

Craniomaxillofacial injuries produce complex wound environments involving various tissue types and treatment strategies. In a clinical setting, care is taken to properly irrigate and stabilize the injury, while grafts are molded in an attempt to maintain physiological functionality and cosmesis. This often requires multiple surgeries and grafts leading to added discomfort, pain and financial burden.

View Article and Find Full Text PDF

At present, no standard manufacturing guideline exists for depositing hydroxyapatite (HA) on implant surfaces. Although animal and in vitro studies have reported on the benefits of using HA-coated implants as well as the risks of dissolution, these short-term studies did not demonstrate that the dissolution of the HA coating leads to a loss of implants. In addition, many in vivo and clinical studies did not include the chemical and structural characterization of the coatings, and thus comparisons between studies are difficult.

View Article and Find Full Text PDF

The purpose is to describe a case of traumatic right extracranial internal carotid artery (EICA) pseudoaneurysm, which is a rare entity and the evolution of treatment from surgery to minimally invasive intervention by endovascular stenting and coiling. We reported a case of traumatic right EICA pseudoaneurysm who presented with multiple cranial nerve palsies. Multiple radiological examinations [including magnetic resonance imaging (MRI) with angiogram, computed tomography angiogram (CTA), and digital subtraction angiogram (DSA)] demonstrated right EICA pseudoaneurysm.

View Article and Find Full Text PDF

A bioactive two-layer coating consisting of hydroxyapatite (HA) and yttria-stabilized zirconia (YSZ) was investigated on cylindrical polyetheretherketone (PEEK) implants using ion beam assisted deposition (IBAD). Post-deposition heat treatments via variable frequency microwave annealing with and without subsequent autoclaving were used to crystallize the as-deposited amorphous HA layer. Microstructural analysis, performed by TEM and EDS, showed that these methods were capable of crystallizing HA coating on PEEK.

View Article and Find Full Text PDF