Implementation of B'More Healthy Communities for Kids: process evaluation of a multi-level, multi-component obesity prevention intervention.

B'More Healthy Communities for Kids was a multi-level, multi-component obesity prevention intervention to improve access, demand and consumption of healthier foods and beverages in 28 low-income neighborhoods in Baltimore City, MD. Process evaluation assesses the implementation of an intervention and monitor progress. To the best of our knowledge, little detailed process data from multi-level obesity prevention trials have been published. Implementation of each intervention component (wholesaler, recreation center, carryout restaurant, corner store, policy and social media/text messaging) was classified as high, medium or low according to set standards. The wholesaler component achieved high implementation for reach, dose delivered and fidelity. Recreation center and carryout restaurant components achieved medium reach, dose delivered and fidelity. Corner stores achieved medium reach and dose delivered and high fidelity. The policy component achieved high reach and medium dose delivered and fidelity. Social media/text messaging achieved medium reach and high dose delivered and fidelity. Overall, study reach and dose delivered achieved a high implementation level, whereas fidelity achieved a medium level. Varying levels of implementation may have balanced the performance of an intervention component for each process evaluation construct. This detailed process evaluation of the B'More Healthy Communities for Kids allowed the assessment of implementation successes, failures and challenges of each intervention component.

Plasma surface modification of artificial corneas for optimal epithelialization.

We have demonstrated that the optimal surface treatment of a polyvinylalcoholcopolymer hydrogel for epithelial cell migration and proliferation is an argon radio frequency (rf) plasma treatment. The surface chemistry of the material was determined prior to each cellular evaluation, allowing us to compare the biological response with a known surface chemistry. The cellular response was carried out in a consistent manner a minimum of three separate runs. We found that the optimal conditions required culturing the cells under constant rotation. Cells became confluent on argon-plasma-treated surfaces coated under several different reactions pressures, and after 2 weeks they became multilayered. Our experiments demonstrated that cells proliferated and extracellular matrix and adhesion proteins were present only when the surface was treated with an argon rf plasma; acetone- and ammonia-treated surfaces did not yield the desired results. Organ culture experiments further demonstrated the efficacy of the argon-treated surfaces. In these experiments, intact keratoprosthetic devices with modified hydrogel surfaces were implanted into rabbit corneas. The excised corneas containing the devices were cultured, and 3 weeks later, using confocal laser scanning microscopy, confluent epithelium was detected on the modified hydrogel surface. This is the first demonstration that rabbit limbal epithelial cells can migrate onto a synthetic cornea containing a modified hydrogel-treated surface and form a confluent surface of epithelium.

Effect of surface plasma treatment on the chemical, physical, morphological, and mechanical properties of totally absorbable bone internal fixation devices.

The purpose of this work was threefold: to enhance the adhesion between the reinforced absorbable calcium phosphate (CaP) fibers and the absorbable polyglycolide acid (PGA) matrix, to improve the hydrolytic degradation of the CaP fibers, and preliminarily to evaluate the cytotoxicity of the plasma treated surface of CaP fibers. A CH4 plasma treatment was used to achieve these goals. The microbond method was used to evaluate the effects of the plasma treatment on the interfacial shear strength between the PGA matrix and CaP fibers. The treatment increased the mean interfacial shear strength of the CaP/PGA composite system by 30%. AFM data showed that CH4-treated CaP fibers had considerable microscopic surface roughness, which facilitated mechanical interlocking between the reinforced CaP fibers and PGA matrix. The untreated and plasma-treated fibers were also subjected to in vitro hydrolytic degradation in a phosphate buffer solution of pH 7.44 at 37 degrees C for up to 15 h. CH4 plasma treatment resulted in a considerable lower polar term of the surface energy and a significantly higher disperse term in water media. This change in the proportion of surface energy terms may reduce the capillary wicking phenomena of water through the CaP fiber/PGA matrix interface. The CaP fiber dissolution studies revealed that both CH4 and Parylene plasma polymer coatings appeared to reduce the solubility of CaP fibers, and that the magnitude of reduction was higher in an acidic than a physiologic pH environment. A preliminary cytotoxicity test revealed that both CH4 and Parylene plasma-treated CaP fibers were noncytotoxic. Additional research should be done to determine the optimum plasma conditions and the possible use of other plasma gases to improve the interfacial shear stress of the composite and the dissolution properties of CaP fibers.

Effect of a combined gamma irradiation and Parylene plasma treatment on the hydrolytic degradation of synthetic biodegradable sutures.

The aim of this study was to alter the hydrolytic degradation property of synthetic absorbable suture fibers so that their mass loss would occur at a shorter time without significantly compromising their tensile strength loss profile. A two-step treatment concept (gamma-irradiation followed by Parylene plasma deposition) was introduced for achieving this aim. Vicryl and Maxon were used as the model compounds to test this new concept. After the treatment, the in vitro hydrolytic degradation properties of Vicryl and Maxon were evaluated by weight loss, tensile breaking strength, heat of fusion and melting temperature, intrinsic viscosity, surface wettability, and surface morphology. The results suggested that gamma-irradiation at a dosage level between 0.2-2.0 Mrad for Vicryl sutures and about 2.0 Mrad for Maxon sutures were the most effective dosages to accelerate the suture mass loss. The subsequent Parylene plasma deposition treatment statistically significantly improved the retention of tensile strength for both gamma-irradiated Vicryl and Maxon sutures and hence counteracted the undesirable gamma-irradiation induced acceleration of tensile strength loss. However, this second-step Parylene plasma treatment extended the suture mass loss to longer periods. These findings were consistent with the observed surface wettability, surface morphology, intrinsic viscosity, and thermal properties. A thin hydrophobic Parylene skin layer wrapped around a suture was responsible for the slower rate in mass and strength loss. This outer skin layer acted as a barrier to not only water but also degradation fragments.

Plasma surface modification of synthetic absorbable sutures.

The aim of the study was to examine the feasibility of using plasma surface modification technology to alter the hydrolytic degradation rate of commercial synthetic absorbable sutures. Size 2-0 Dexon, Vicryl, PDSII, and Maxon sutures were tested. They were treated by two different surface modification techniques: parylene deposition and plasma gases (Methane, trimethylsilane, and tetrafluoroethene). The thickness of surface treatment ranged from 200 to 1000 A. The treated sutures were subject to in vitro hydrolytic degradation in phosphate buffer of pH = 7.4 at 37 degrees C for up to 120 days. The tensile breaking strength, weight loss, surface wettability, bending stiffness, and surface morphology were evaluated. The results indicated that the concept of plasma surface treatment for altering the hydrolytic degradation of synthetic absorbable sutures was feasible, and the level of improvement depended on the type of sutures, the treatment conditions, and the duration of hydrolysis. Vicryl and PDSII sutures showed overall the best improvement in tensile strength retention among the four commercial sutures. Dexon and Maxon sutures, however, exhibited only marginal improvement. The observed improvement in tensile strength retention appeared to be related to the increasing hydrophobicity of the sutures. The surface treatments did not adversely affect the bending stiffness of the sutures and no visible surface morphological changes were observed. Refinements and optimization of the surface treatment conditions are needed for achieving the maximum advantage of the proposed concept, particularly shielding the harmful effect of uv during plasma treatment.