Surface Modification of Medical-Grade Titanium and Polyvinyl Chloride with a Novel Catechol-Terminated Compound Containing Zwitterionic Sulfobetaine Functionality for Antibacterial Application.

Healthcare-associated infection, mainly through medical device-associated infection, remains a critical issue in hospital care. Bacterial adhesion, proliferation, and biofilm formation on the device surface have been considered the foremost cause of medical device-associated infection. Different means have been explored to reduce microbial attachment and proliferation, including forming a bactericidal or microbial adhesion-resistant surface layer.

A Facile Surface Modification Scheme for Medical-Grade Titanium and Polypropylene Using a Novel Mussel-Inspired Biomimetic Polymer with Cationic Quaternary Ammonium Functionalities for Antibacterial Application.

Medical device-associated infection remains a critical problem in the healthcare setting. Different clinical- or device-related methods have been attempted to reduce the infection rate. Among these approaches, creating a surface with bactericidal cationic functionality has been proposed.

Studies of Mercaptosuccinic Acid-Crosslinked Chitosan Hydrogel with Grafted Cinnamaldehyde and Silver Nanoparticles for Antibacterial Biomedical Application.

For the effective clinical antibacterial application of biomaterials, such as for wound management and tissue repair, the biomaterials need to show proper antibacterial capability as well as non-cytotoxicity. Furthermore, the material needs to have suitable mechanical characteristics for further medical use. Chitosan hydrogel is a potential candidate for various antibacterial biomedical applications due to its amine functionalities that lead to antimicrobial characteristics.

Surface Modification of Polyurethane Membrane with Various Hydrophilic Monomers and N-Halamine: Surface Characterization and Antimicrobial Properties Evaluation.

Reducing microbial infections associated with biomedical devices or articles/furniture noted in a hospital or outpatient clinic remains a great challenge to researchers. Due to its stability and low toxicity, the N-halamine compound has been proposed as a potential antimicrobial agent. It can be incorporated into or blended with the FDA-approved biomaterials.

Effect of alkyl chain length and fluorine content on the surface characteristics and antibacterial activity of surfaces grafted with brushes containing quaternized ammonium and fluoro-containing monomers.

Although considerable efforts have been made to vary the alkyl chain length in the quaternary ammonium compounds (QACs) for optimizing the antibacterial activity, only few researchers have systematically investigated the combinatory effects of alkyl chain length and another acryl monomers with the different chemical configuration on the antibacterial activity of the modified substrate. In this study, by surface grafting of various copolymeric brushes, different modified cotton substrates were prepared by surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization reaction for exploring the effects of alkyl chain length of QACs and the fluorine content on antibacterial and anti-microbial adhesion characteristics. The quaternized monomers used were prepared by quaternization of 2-(dimethylamino) ethyl methacrylate (DMAEMA) with 1-bromooctane (DMAEMA + 8), and 1-bromopropane (DMAEMA + 3).

Studies of the Sulfonated Hydrogenated Styrene-Isoprene-Styrene Block Copolymer and Its Surface Properties, Cytotoxicity, and Platelet-Contacting Characteristics.

Styrenic thermoplastic elastomers (TPEs) consist of styrenic blocks. They are connected with other soft segments by a covalent linkage and are widely used in human life. However, in biomedical applications, TPEs need to be chemically hydrogenated in advance to enhance their properties such as strong UV/ozone resistance and thermal-oxidative stability.

Studies of surface grafted collagen and transforming growth factor β1 combined with cyclic stretching as a dual chemical and physical stimuli approach for rat adipose-derived stem cells (rADSCs) chondrogenesis differentiation.

The adipose-derived stem cell has been used in various regenerative medicine research due to its multiple differentiation capabilities. Developing a stable and quick approach for the differentiation of stem cells is a critical issue in tissue regenerative field. In this investigation, rat adipose-derived stem cells (rADSCs) were seeded onto the type I collagen/transforming growth factor β1 (TGF-β1) immobilized polydimethylsiloxane (PDMS) substrate and then combined with short term dynamic stretching stimulation (intermittent or continuous stretching for 6 h) to induce the rADSCs chondrogenesis differentiation using the induction medium without growth factors added in vitro.

Studies of zwitterionic sulfobetaine functionalized polypropylene surface with or without polyethylene glycol spacer: surface characterization, antibacterial adhesion, and platelet compatibility evaluation.

Microbial adhesion reduction as well as platelet compatibility improvement have been suggested as the key requirements for developing blood-contacting synthetic biomaterials. Surface grafting of hydrophilic polyethylene glycol chains or alkyl chains with zwitterionic terminal ends has been proposed for reducing microbial or platelet adhesion. Nonetheless, none has been reported to incorporate both polyethylene glycol and zwitterionic terminal functionality on the same surface-grafted alkyl chain.

Sulfonation and Characterization of Tert-Butyl Styrene/Styrene/Isoprene Copolymer and Polypropylene Blends for Blood Compatibility Applications.

Hydrogenated styrenic block copolymers (HSBCs) have been used in medical tubing for many years due to their high clarity, flexibility, kink resistance, and toughness. However, when it comes to blood storage applications, HSBC compounds' market has been limited because of their high hydrophobicity, which may trigger platelet adhesion when contacting with blood. HSBC needs to be physically or chemically modified in advance to make it blood compatible; however, HSBC has strong UV/ozone resistance, thermooxidative stability, and excellent processing capability, which increases the difficulty of the chemical modification process as unsaturated dienes has been converted to saturated stable midblocks.

Studies of proliferation and chondrogenic differentiation of rat adipose stem cells using an anti-oxidative polyurethane scaffold combined with cyclic compression culture.

The adipose stem cell is a potential candidate for the autologous chondrocytes repairing approach because of the abundance of fat in the animal body and its versatile differentiation capability. In this study, rat adipose stem cells (rASCs) were seeded into anti-oxidative N-acetylcysteine (NAC) grafted polyurethane (PU) scaffold and then combined with short dynamic compressive stimulation (24 h) to induce rASCs chondrogenesis differentiation in vitro. The inner pore surface of the PU scaffold was first modified via alginate and type I collagen to promote rASCs adherence.

Studies of polypropylene surface modified with novel beta-thiopropionate-based zwitterionic polymeric brush: synthesis, surface characterization, and significantly reduced fouling characteristics evaluation.

Creating a surface with anti- or reduced fouling characteristics can lead to a reduction in nonspecific protein adsorption as well as the bacterial adhesion and platelet adhesion/activation that occur as follows. A zwitterionic polymer that consists of both cationic and anionic functionalities have been reported as an effective material to achieve these goals, likely resulted from the strongly-adsorbed hydration layer after being immersed in the physiological environment. In this investigation, a novel beta-thiopropionate-based zwitterionic monomer, 2-ammonio-3-((3-(2-hydroxy-3-(methacryloyloxy)propoxy)-3-oxopropyl)thio)-3-methylbutanoate (DPAMA), was synthesized through a facial process.

Studies of PET nonwovens modified by novel antimicrobials configured with both -halamine and dual quaternary ammonium with different alkyl chain length.

This work describes the synthesis of novel antimicrobial agents consisting of -halamine and dual quaternary ammonium with different alkyl chain lengths and their antimicrobial applications for PET nonwovens. The antimicrobial agents were grafted onto PET nonwovens esterification with a crosslinker, 1,2,3,4-butanetetracarboxylic acid (BTCA). The cyclic amide structure in the antimicrobial agents could be easily converted to -halamine after immersion in a diluted chlorine bleach solution.

A facile novel fluorocarbon copolymer solution coating process for improving platelet compatibility of titanium.

Titanium (Ti) and its alloys possess mechanical properties that are desirable in many biomedical applications compared to other metals. Furthermore, the native metal oxide layer that prevents further oxidation is also known to be biocompatible. However, clinical findings have shown that titanium and its alloys are prone to adverse bioreactions such as platelet adhesion and activation which could lead to thrombogenic complications.

Studies of magnetic alginate-based electrospun matrices crosslinked with different methods for potential hyperthermia treatment.

The magnetic electrospun mats were lately established as an innovative biomaterial for hyperthermic cancer treatment. Unlike those surface-modified magnetic nanoparticles that may not firmly adhere onto the tumor for long-term duration, the magnetic mats with nanofibrous structure can promote cell adhesion and kill the tumor directly within an alternating magnetic field. However, most magnetic electrospun mats were fabricated using non-biodegradable polymers and organic solvents, causing the problems of removal after therapy and the suspected biotoxicity associated with residual solvent.

Spin-coated Au-nanohole arrays engineered by nanosphere lithography for a Staphylococcus aureus 16S rRNA electrochemical sensor.

The nanopatterning of gold nanoparticle (AuNP) arrays on an indium tin oxide (ITO) electrode using efficient and low-cost methods is described. This process used nanosphere lithography (NSL) encompassing the deposition of monolayered Polystyrene (PS) followed by a convective self-assembly drop coating protocol onto the ITO substrate that further acted as the mask after the AuNP assembly. The results showed that spin-coating allowed AuNPs to follow the contour and adhere to the PS nanospheres.

Genetic Polymorphisms in Inflammasome-Dependent Innate Immunity among Pediatric Patients with Severe Renal Parenchymal Infections.

Background: Inflammasome innate immune response activation has been demonstrated in various inflammatory diseases and microbial infections. However, to our knowledge, no study has examined the inflammasome-dependent pathways in patients with urinary tract infection. Defective or variant genes associated with innate immunity are believed to alter the host's susceptibility to microbial infection.

Genetic polymorphisms in Toll-like receptors among pediatric patients with renal parenchymal infections of different clinical severities.

Background: Although several studies have suggested single gene defects or variations in the genes associated with host immune response could confer differences in susceptibility to urinary pathogen invasion, no studies have examined the genetic polymorphisms in various toll-like receptors (TLRs) that activate innate immune responses in pediatric renal parenchymal infections of different clinical severities, namely acute pyelonephritis and the clinically more severe disease, acute lobar nephronia.

Methodology: Patients who fulfilled the diagnostic criteria for acute pyelonephritis (APN) and acute lobar nephronia (ALN) without underlying diseases or structural anomalies, except for vesicoureteral reflux (VUR), were enrolled. Genotyping of the single nucleotide polymorphisms (SNPs) in the genes encoding TLR-1, TLR-2, TLR-4, TLR-5, and TLR-6 was performed by matrix-assisted laser desorption/ionization time-of-flight-based mini-sequencing analysis.

Splenic hemangiopericytoma in a one-month-old infant.

Hemangiopericytoma is an uncommon tumor that occurs mostly in middle-aged adults. There have been only sporadic case reports of splenic involvement, and in all but one the treatment has been total splenectomy. We present a one-month-old boy with splenic hemangiopericytoma treated with partial splenectomy.

Nephromegaly is a significant risk factor for renal scarring in children with first febrile urinary tract infections.

Purpose: We determined whether nephromegaly on ultrasound can be used to identify patients with urinary tract infection at increased risk for renal scarring, and we investigated the effect of vesicoureteral reflux on renal scarring.

Materials And Methods: We enrolled hospitalized patients with a first febrile urinary tract infection. All patients underwent renal ultrasound and most patients underwent voiding cystourethrography.

Nasopharyngeal carriage of Streptococcus pneumoniae in Taiwan before and after the introduction of a conjugate vaccine.

Background: The heptavalent pneumococcal conjugate vaccine was introduced in Taiwan in October 2005. To evaluate the effect of the vaccination, we conducted an active, prospective, large-scale, long-term, and multicenter study to assess the prevalence of nasopharyngeal Streptococcus pneumoniae carriage in Taiwanese children.

Methods: This study was performed at three tertiary teaching hospitals in northern, central, and southern Taiwan.