Surfactant Modulated Phase Transitions of Liquid Crystals Confined in Electrospun Coaxial Fibers.

Confinement of liquid crystals (LCs) in polymeric fibers offers a promising strategy to control liquid crystal response to external stimuli. Here, the confinement of 4-cyano-4'-pentylbiphenyl (5CB), a nematic liquid crystal, within the core of coaxially electrospun fibers composed of poly(vinylpyrrolidone) (PVP) containing different surfactants is discussed. The effects of surfactant type, surfactant concentration, and core flow rate (confinement) on the LC behavior were demonstrated using polarized optical microscopy, scanning electron microscopy, differential scanning calorimetry, Raman, and dielectric spectroscopy. Introduction of surfactant dopants of varying hydrophilic and hydrophobic components into the sheath altered the interfacial interaction between the PVP sheath and the 5CB core of the fibers. Significant effects on the LC nematic to isotropic phase transition were attributed to changes in surface anchoring between the sheath and core. Confinement of nematic LCs in surfactant doped polymeric fibers demonstrates a facile method for tuning LC phase behavior.

Air Activated Self-Decontaminating Polydicyclopentadiene PolyHIPE Foams for Rapid Decontamination of Chemical Warfare Agents.

The threat of chemical warfare agents (CWA) compels research into novel self-decontaminating materials (SDM) for the continued safety of first-responders, civilians, and active service personnel. The capacity to actively detoxify, as opposed to merely sequester, offending agents under typical environmental conditions defines the added value of SDMs in comparison to traditional adsorptive materials. Porous polymers, synthesized via the high internal phase emulsion (HIPE) templating, provide a facile fabrication method for materials with permeable open cellular structures that may serve in air filtration applications. PolyHIPEs comprising polydicyclopentadiene (polyDCPD) networks form stable hydroperoxide species following activation in air under ambient conditions. The hydroperoxide-containing polyDCPD materials react quickly with CWA simulants, Demeton-S and 2-chloroethyl ethyl sulfide, forming oxidation products as confirmed via gas chromatography mass spectrometry. The simplicity of the detoxification chemistry paired with the porous foam form factor presents an exciting opportunity for the development of self-decontaminating filter media.

Enhancing the fouling resistance of biocidal urethane coatings via surface chemistry modulation.

A group of novel cross-linked polyurethane materials with varying ratios of hydroxyl-terminated macrodiols and tethered quaternary ammonium biocides have been prepared. The resulting materials had a wide range of thermal, mechanical, and surface properties, dictated by the macrodiol composition and biocide concentration. The complex interplay between surface chemistry and biocide concentration was shown to have a profound effect on the fouling resistance of these materials. While the combination of quaternary ammonium salt (QAS) diols with poly(tetramethylene oxide) macrodiols did not result in any enhancement of fouling resistance, addition of biocides to poly(ethylene glycol)-containing urethanes resulted in up to a 90% increase in biocidal activity compared to control materials while reducing the ability for microbes to adhere to the surface by an additional 60%. Materials prepared with polybutadiene macrodiols underwent a thermally induced oxidation, resulting in partial decomposition of the quaternary ammonium salt biocide and joint antimicrobial activity arising from remaining QAS and peroxide compounds.

Short-Term Outcomes of the Boston Brace 3D Program Based on SRS and SOSORT Criteria: A Retrospective Study.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is characterized by a lateral curvature of the spine with a Cobb angle greater than 10 degrees, accompanied by rotation of the vertebral body. Bracing has been shown to be effective in halting the progression of at-risk curves, and, in some cases, even improving the Cobb angle by 6° or more. The Boston Brace 3D is part of the Boston Orthotics and Prosthetics standardized scoliosis program. The orthosis is custom-fabricated from scans, computer-aided design (CAD), and computer-aided manufactured (CAM) thoracolumbosacral orthosis used in the non-operative management of AIS. AIM: To evaluate the outcomes of a scoliosis program utilizing the Boston Brace 3D orthosis for patients with AIS, based on SRS and SOSORT criteria. DESIGN: Retrospective study. METHODS: An electronic medical records search was conducted to identify first-time brace wearers fitted between 1 January 2018, and 30 June 2019, at Boston Orthotics and Prosthetics Boston area clinics that met the SRS/SOSORT research guidelines. The initial out-of-brace, in-brace, and last follow-up X-rays (taken at least 12 months after fitting) were compared. RESULTS: 84% of patients presenting with a single curve and 69% of patients with a double curve saw their curves improve (reduced 6° or more) or remain unchanged (±5°). Thirty-one patients started with a single curve between 25° and 30°, and thirty-two presented at 30° or below. Fifty-nine patients started with a double curve between 25° and 30°, and 59 patients presented at 30° or below. In general, the patients who wore their brace for more hours per day saw improved results. CONCLUSION: The Boston Brace 3D program is effective in controlling (and in some cases improving) curve progression in the non-operative management of adolescent idiopathic scoliosis. The approach is a repeatable system, as shown in this cohort of thirteen clinicians across six area clinics following the Boston Brace 3D clinical guidelines.

The Boston Brace System philosophy, biomechanics, design & fit.

The Boston Brace System developed in the early 1970's by Dr John Hall and Bill Miller, CPO, is a logical, multidisciplinary approach to the treatment of idiopathic scoliosis. The Brace itself is but one component of the Brace system. The clinical team consists of patient, family, orthopedist, orthotist, physical therapist and nurse. Each team member needs to have a working knowledge of each others discipline, and educate the patient on his/her roll of the treatment plan. If the patient is not educated and understands the process, the logic behind the process and the critical roll they play- then the whole system has been compromised. The Boston Brace itself is one of the most widely studied orthosis used in the conservative management of scoliosis. It has been shown that orthotist training and skill, as well as the ability to assess and modify the fit in 3D have a positive influence on patient outcome. This chapter will discuss the philosophy, biomechanics, design, fit and adjustments necessary for a successful outcome. By following the basic tenants of the system, and maintaining the patient focus, the goal of having a stable spine in adulthood can be obtained. It takes a team effort. This outline will take about how to construct and evaluate the orthosis to maximize fit and function.

Synthesis and kinetics of disassembly for silyl-containing ethoxycarbonyls using fluoride ions.

In this study, a series of silyl-containing ethoxycarbonates and ethoxycarbamates on electron poor anilines and phenols were synthesized and their kinetics of disassembly determined in real-time upon exposure to fluoride ion sources at room temperature. The results provide a greater understanding of stability and kinetics for silyl-containing protecting groups that eliminate volatile molecules upon removal, which will allow for simplification of orthogonal protection in complex organic molecules.

Hemostatic and Absorbent PolyHIPE-Kaolin Composites for 3D Printable Wound Dressing Materials.

A novel hemostatic and absorbent wound dressing material compatible with 3D printing is developed to address deficiencies in current wound dressing protocol. The design involves an open celled, microporous hydrogel foam via a high internal phase emulsion (HIPE) template with biocompatible components and tunable hemostatic character by kaolin loading, the viscosity and cure kinetics of which are tailored for 3D printing applications. The use of nontoxic mineral oil organic phase results in cytocompatability with human dermal fibroblasts. Kaolin distribution is shown by X-ray diffraction and elemental dispersive spectroscopy to be exfoliated and dispersed in the hydrogel dressing. In addition to demonstrating high fluid absorption and noncytotoxicity of relevant cell lines, the high internal phase emulsion polymers (polyHIPEs) also match the hemostatic performance of commercial wound dressing materials. Furthermore, the polyHIPEs display the requisite rheological properties for 3D printing that result in the fabrication of a prototype dressing with hierarchical porosity and a large number of controllable form factors.

Hemostatic kaolin-polyurethane foam composites for multifunctional wound dressing applications.

There are numerous challenges associated with the acute care of traumatic limb injuries in forward military settings. A lack of immediate medical facilities necessitates that the wound dressing perform multiple tasks including exudate control, infection prevention, and physical protection of the wound for extended periods of time. Here, kaolin was incorporated into recently developed robust polyurethane (PU) hydrogel foams at 1-10wt% in an effort to impart hemostatic character. ATR-IR and gel fraction analysis demonstrated that the facile, one-pot synthesis of the PU hydrogel was unaffected by kaolin loading, as well as the use of a non-toxic catalyst, which significantly improved cytocompatibility of the materials. Kaolin was generally well dispersed throughout the PU matrix, though higher loadings exhibited minor evidence of aggregation. Kaolin-PU composites exhibited burst release of ciprofloxacin over 2h, the initial release rates of which increased with kaolin loading. Kaolin loading imparted excellent hemostatic character to the PU foams at relatively low loading levels (5wt%). This work demonstrates the simple and inexpensive synthesis of robust, hemostatic, and absorptive kaolin-PU foams that have promising potential as multifunctional wound dressing materials.

Environmental Effects on Zirconium Hydroxide Nanoparticles and Chemical Warfare Agent Decomposition: Implications of Atmospheric Water and Carbon Dioxide.

Zirconium hydroxide (Zr(OH)4) has excellent sorption properties and wide-ranging reactivity toward numerous types of chemical warfare agents (CWAs) and toxic industrial chemicals. Under pristine laboratory conditions, the effectiveness of Zr(OH)4 has been attributed to a combination of diverse surface hydroxyl species and defects; however, atmospheric components (e.g., CO2, H2O, etc.) and trace contaminants can form adsorbates with potentially detrimental impact to the chemical reactivity of Zr(OH)4. Here, we report the hydrolysis of a CWA simulant, dimethyl methylphosphonate (DMMP) on Zr(OH)4 determined by gas chromatography-mass spectrometry and in situ attenuated total reflectance Fourier transform infrared spectroscopy under ambient conditions. DMMP dosing on Zr(OH)4 formed methyl methylphosphonate and methoxy degradation products on free bridging and terminal hydroxyl sites of Zr(OH)4 under all evaluated environmental conditions. CO2 dosing on Zr(OH)4 formed adsorbed (bi)carbonates and interfacial carbonate complexes with relative stability dependent on CO2 and H2O partial pressures. High concentrations of CO2 reduced DMMP decomposition kinetics by occupying Zr(OH)4 active sites with carbonaceous adsorbates. Elevated humidity promoted hydrolysis of adsorbed DMMP on Zr(OH)4 to produce methanol and regenerated free hydroxyl species. Hydrolysis of DMMP by Zr(OH)4 occurred under all conditions evaluated, demonstrating promise for chemical decontamination under diverse, real-world conditions.

Novel Methods of Producing Low-Reflectance Coatings Utilizing Synergistic Effects of Polymer Phase Separation.

Novel methods were developed to generate and characterize surface structures formed from polymer segregation within a powder coating system. A blend of unique acrylic polyol resins and low concentrations of matting agent afforded a durable coating exhibiting consistent low reflectance. An enhanced synergistic effect was observed from the phase separation and domain formation of the two polymeric resins with varying pendent hydroxyl group functionality and the incorporated matting agents. Together the domains and incorporated matting agents produced a significantly lower reflectance coating than the matting agent in combination with either polymeric resin alone. The rigorous thermal, optical, and spectroscopic analysis of the pigmented coating and control coatings culminated in the complete characterization of polymeric phases within the resulting coatings. Raman analysis of the control coatings via a distinct spectroscopic handle allowed for positive identification of the segregated polymer resins within the coating structure. Domains observed by optical microscopy within the control coating structure were chemically identified via Raman analysis as the high-hydroxyl content resin. Subsequent Raman mapping of the peak intensity over an entire cross-section provided consistent evidence for positive identification of the polymeric composition within the domain.

Decontamination of chemical-warfare agent simulants by polymer surfaces doped with the singlet oxygen generator zinc octaphenoxyphthalocyanine.

Using reactive singlet oxygen (1O2), the oxidation of chemical-warfare agent (CWA) simulants has been demonstrated. The zinc octaphenoxyphthalocyanine (ZnOPPc) complex was demonstrated to be an efficient photosensitizer for converting molecular oxygen (O2) to 1O2 using broad-spectrum light (450-800 nm) from a 250 W halogen lamp. This photosensitization produces 1O2 in solution as well as within polymer matrices. The oxidation of 1-naphthol to naphthoquinone was used to monitor the rate of 1O2 generation in the commercially available polymer film Hydrothane that incorporates ZnOPPc. Using electrospinning, nanofibers of ZnOPPc in Hydrothane and polycarbonate were formed and analyzed for their ability to oxidize demeton-S, a CWA simulant, on the surface of the polymers and were found to have similar reactivity as their corresponding films. The Hydrothane films were then used to oxidize CWA simulants malathion, 2-chloroethyl phenyl sulfide (CEPS), and 2-chloroethyl ethyl sulfide (CEES). Through this oxidation process, the CWA simulants are converted into less toxic compounds, thus decontaminating the surface using only O2 from the air and light.

Coatings capable of germinating and neutralizing Bacillus anthracis endospores.

Endospores are formed by various bacterial families, including Bacillus and Clostridium, in response to environmental stresses as a means to survive conditions inhospitable to vegetative growth. Although metabolically inert, the endospore must interact with its environment to determine an optimal time to return to a vegetative state, a process known as germination. Germination has been shown to occur in response to a variety of chemical stimuli from specific nutrient germinants including amino acids, sugars and nucleosides. This process is known to be mediated primarily by the GerA family of spore-specific receptor proteins which initiates a signal transduction cascade that results in a return of oxidative metabolism in response to germinant receptor interactions. Herein, we report the development of a novel coating system capable of germinating B. anthracis endospores, followed by rapid killing of the vegetative bacteria by a novel incorporated amphiphilic biocide. The most effective formulation tested exhibited an ability to germinate and kill B. anthracis endospores and vegetative bacteria, respectively. The formulation reported resulted in a 90% reduction in as little as 5 min, and a 6 log reduction by 45 min.

Zwitterionic polyurethane hydrogels derived from carboxybetaine-functionalized diols.

The synthesis of novel zwitterionic polyurethane hydrogels with tunable water uptake via the polymerization of protected carboxybetaine-functionalized diols with polyisocyanate oligomers is presented. Post-polymerization hydrolysis of a diol-segment side chain establishes zwitterionic carboxybetaine functionalities that facilitate water uptake via the enhanced hydration capacities surrounding the opposing charges of the diol component. Tunable hydration of these materials, ranging from 24 to 250% solution uptake (based on the dry polymer weight), is achieved by controlling the structural characteristics of the diol precursor, such as ammonium/carboxylate spacing and ethyl ester hydrolysis conditions (i.e., exposure time to an aqueous base).

2011 SOSORT guidelines: Orthopaedic and Rehabilitation treatment of idiopathic scoliosis during growth.

BACKGROUND: The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT), that produced its first Guidelines in 2005, felt the need to revise them and increase their scientific quality. The aim is to offer to all professionals and their patients an evidence-based updated review of the actual evidence on conservative treatment of idiopathic scoliosis (CTIS). METHODS: All types of professionals (specialty physicians, and allied health professionals) engaged in CTIS have been involved together with a methodologist and a patient representative. A review of all the relevant literature and of the existing Guidelines have been performed. Documents, recommendations, and practical approach flow charts have been developed according to a Delphi procedure. A methodological and practical review has been made, and a final Consensus Session was held during the 2011 Barcelona SOSORT Meeting. RESULTS: The contents of the document are: methodology; generalities on idiopathic scoliosis; approach to CTIS in different patients, with practical flow-charts; literature review and recommendations on assessment, bracing, physiotherapy, Physiotherapeutic Specific Exercises (PSE) and other CTIS. Sixty-five recommendations have been given, divided in the following topics: Bracing (20 recommendations), PSE to prevent scoliosis progression during growth (8), PSE during brace treatment and surgical therapy (5), Other conservative treatments (3), Respiratory function and exercises (3), Sports activities (6), Assessment (20). No recommendations reached a Strength of Evidence level I; 2 were level II; 7 level III; and 20 level IV; through the Consensus procedure 26 reached level V and 10 level VI. The Strength of Recommendations was Grade A for 13, B for 49 and C for 3; none had grade D. CONCLUSION: These Guidelines have been a big effort of SOSORT to paint the actual situation of CTIS, starting from the evidence, and filling all the gray areas using a scientific method. According to results, it is possible to understand the lack of research in general on CTIS. SOSORT invites researchers to join, and clinicians to develop good research strategies to allow in the future to support or refute these recommendations according to new and stronger evidence.

Development of broad-spectrum antimicrobial latex paint surfaces employing active amphiphilic compounds.

With the increase in antibiotic-resistant microbes, the production of self-decontaminating surfaces has become an area of research that has seen a surge of interest in recent years. Such surfaces, when incorporated into commercial products such as children's toys, medical devices and hospital surfaces could reduce the number of infections caused by pathogenic microorganisms. A number of active components for self-decontaminating surfaces have been investigated, including common antibiotics, metal ions, quaternary ammonium salts (QAS), and antimicrobial peptides (AMP). A recent research focus has been development of a wide range of amphiphilic antimicrobial additives that when combined with modern low volatile organic compound (VOC), water-based paints leads to a surface concentration of the active compounds as the coating cures. Herein we report the development of antimicrobial coatings containing a variety of additives, both QAS and AMP that are active against a broad-spectrum of potentially pathogenic bacteria (1-7 log kill), as well as enveloped viruses (2-7 log kill) and fungi (1-2 log kill). Additionally, these additives were compatible with water-dispersed acrylate coatings (latex paint) which have a broad range of real world applicability, and remained active for multiple challenges and when exposed to various cleaning scenarios in which they might encounter in real world situations.

Synthesis and development of a multifunctional self-decontaminating polyurethane coating.

A unique, durable, nonleaching antimicrobial urethane coating possessing energy-dampening properties is reported. Five novel diol-functionalized quaternary ammonium bromide salts were designed, synthesized, and cross-linked with a commercial polyisocyanate to afford novel multifunctional self-decontaminating coatings. Leaching of the antimicrobial into the environment is eliminated because of the biocidal tether. The effectiveness of these molecules to self-concentrate at the air-polymer interface without addition of other surface modifying additives proved extremely advantageous, and consequently resulted in microphase separation as confirmed by AFM. The coatings were designed to continuously decontaminate against a variety of pathogenic bacteria in addition to affording preliminary dampening properties. Minimum inhibitory concentration studies as well as surface antimicrobial evaluations were conducted using both Gram-positive and Gram-negative bacteria. Additionally, viscoelastic properties, hardness, tack, and surface energy measurements were used to correlate with coating performance.

Development of antimicrobial peptides (AMPs) for use in self-decontaminating coatings.

Antimicrobial peptides (AMPs) are a class of short polypeptides usually associated with the host organism's innate immune system. AMPs have been identified in a wide range of host organisms, including plants, amphibians, fish, and humans. These peptides usually consist of 30-100 amino acids and are most often cationic. In addition to a net positive charge, AMPs often are amphipathic, containing both hydrophobic and hydrophilic domains. This property allows for increased interaction with and insertion into negatively charged cell walls and membranes of microbes. Because of the prevalence of antibiotic resistance among common human pathogens, recent research into AMPs has revolved around the attempt to increase the availability of drugs to which microbes are susceptible. Because the mechanism of kill for AMPs is different from that of most conventional antibiotics, which tend to be very specific in their targets, AMPs are thought to be a very attractive future substitute for traditional antibiotics. The development of novel self-decontaminating surfaces containing two AMPs previously isolated from Chrysophrys major is reported. These AMPs, Chrysophsin-1 and -3, demonstrated 1-4 logs kill of both Gram-positive and Gram-negative bacteria when incorporated into control acrylic coating systems.

Terminology - glossary including acronyms and quotations in use for the conservative spinal deformities treatment: 8th SOSORT consensus paper.

BACKGROUND: This report is the SOSORT Consensus Paper on Terminology for use in the treatment of conservative spinal deformities. Figures are provided and relevant literature is cited where appropriate. METHODS: The Delphi method was used to reach a preliminary consensus before the meeting, where the terms that still needed further clarification were discussed. RESULTS: A final agreement was found for all the terms, which now constitute the base of this glossary. New terms will be added after being discussed and accepted. DISCUSSION: When only one set of terms is used for communication in a place or among a group of people, then everyone can clearly and efficiently communicate. This principle applies for any professional group. Until now, no common set of terms was available in the field of the conservative treatment of scoliosis and spinal deformities. This glossary gives a common base language to draw from to discuss data, findings and treatment.

Surface self-concentrating amphiphilic quaternary ammonium biocides as coating additives.

A variety of amphiphilic quaternary dimethylammonium compounds bearing n-alkyl and oxyethylene groups have been designed and synthesized as antimicrobial additives for use in self-decontaminating surfaces. The effectiveness of these additives stems from a unique ability to self-concentrate at the air-polymer interface without the incorporation of exotic perfluorinated or polymeric functionalities. X-ray photoelectron spectroscopy analysis reveals surface enrichment as high as 18-fold, providing a 7-log reduction of both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The migration to the surface is a consequence of the hydrophobicity of the additive within the hydrophilic polyurethane resin, over which an unprecedented level of control can be exerted by altering the lengths of the n-alkyl and oxyethylene groups. Thus, for the first time, specific surface and bulk coating concentrations can be achieved as desired using a single class of antimicrobial additives.

Evidence for singlet-oxygen generation and biocidal activity in photoresponsive metallic nitride fullerene-polymer adhesive films.

The adhesive properties, as measured by bulk tack analysis, are found to decrease in blends of isomerically pure Sc3N@I(h)-C80 metallic nitride fullerene (MNF) and polystyrene-block-polyisoprene-block-polystyrene (SIS) copolymer pressure-sensitive adhesive under white light irradiation in air. The reduction of tack is attributed to the in situ generation of 1O2 and subsequent photooxidative cross-linking of the adhesive film. Comparisons are drawn to classical fullerenes C60 and C70 for this process. This work represents the first demonstration of 1O2 generating ability in the general class of MNFs (M3N@C80). Additional support is provided for the sensitizing ability of Sc3N@I(h)-C80 through the successful photooxygenation of 2-methyl-2-butene to its allylic hydroperoxides in benzene-d(6) under irradiation at 420 nm, a process that occurs at a rate comparable to that of C(60). Photooxygenation of 2-methyl-2-butene is found to be influenced by the fullerene sensitizer concentration and O2 flow rate. Molar extinction coefficients are reported for Sc3N@I(h)-C80 at 420 and 536 nm. Evaluation of the potential antimicrobial activity of films prepared in this study stemming from the in situ generation of 1O2 led to an observed 1 log kill for select Gram-positive and Gram-negative bacteria.