Topical gel containing Polysiloxanes and hyaluronic acid for skin scar: Formulation design, characterization, and In vivo activity.

BACKGROUND: Scar formation is undesirable both cosmetically and functionally. It shows that silicone gel is effective in preventing and improving scars formed due to a wound formation after injury. OBJECTIVES: This study investigates whether a silicone gel composition based on a novel concept of infusing a biologically active material such as hyaluronic acid and/or salts with various polysiloxane derivatives in a specific proportion to achieve desired viscosity range and their action has a synergistic beneficial effect on skin scar after injury. METHODS: We have developed a topical gel utilizing a combination of emulsifiers, sodium hyaluronate, polysiloxane, and its derivatives. The method of preparation comprises mixing of aqueous phase dispersion and polysiloxanes blend under stirring at room temperature. RESULTS: It results in the formation of a homogenous smooth gel formulation. The developed topical gel formulation was characterized for physicochemical properties, rheology, stability, and anti-scar activity in Wistar rats. It was found that the developed formulation system consists of desirable attributes for skin applications. In vivo investigation of developed polysiloxane gel formulation for anti-scar activity shown promising outcomes compared to marketed product (Kelo-cote scar gel). Furthermore, a histopathology study of healed skin tissues observed the formation of microscopic skin structures compared to the Kelo-cote scar gel. CONCLUSIONS: It indicates that the combination of polysiloxanes and sodium hyaluronate resulting an improvement in anti-scar activity compared to the marketed product containing polysiloxanes alone.

Sichere Diagnostik der Implantatrotation im hochauflösenden Ultraschall in Abhängigkeit vom Implantathersteller.

Rotation of an anatomical breast implant may require revisional surgery. High-resolution ultrasound can help determine the exact implant alignment. However, the directional markings of anatomical implants are implemented very inconsistently by manufacturers. Therefore, a definite diagnosis is often not possible without precise knowledge of the expected imaging. The aim of this work is a differentiation of the imaging of common implant brands in high-resolution ultrasound. Methods To simulate an authentic imaging, anatomical implants were viewed through abdominal skin thinned to 1.5-2 cm, which was obtained during a classic abdominoplasty. Implants from the companies Allergan, Eurosilicone, Mentor, Motiva, Nagor, Polytech and Sebbin were compared. The marking positions and dimensions were documented by ultrasound. Results Based on placement and shape, a clear allocation between alignment and manufacturer is basically possible among the implants used. The base plate and caudal markers could be clearly visualised for all brands. In Polytech implants, however, the visible structural change is limited to a very small central area. The visualisation of directional marks, base plate and implant shell also allow conclusions to be drawn about the manufacturer. In high-resolution ultrasound, a fast and reliable diagnosis of implant alignment is possible for all implants examined. Also it was possible to make a clear allocation between implant and manufacturer in this context. Flip over of the implant can also be reliably depicted. The cataloguing of the markings summarised here can be used to determine the exact alignment of the implant and thus provide diagnostic certainty, especially if the brand is unknown.

Retrospective multicenter cohort analysis of 621 cases of BellaGel silicone breast implants with study of physicochemical properties and surface topography.

This study aimed to assess the effectiveness and safety of BellaGel implants after implantation in Asian women and inform surgeons of another option for use in breast augmentation and reconstruction. This study was conducted in eight hospitals from November 27, 2015 to April 30, 2018. All patients underwent augmentation mammoplasty or implant-based breast reconstruction with BellaGel implants. Complication rates were compared between groups, and the cumulative hazard function was compared using the Kaplan-Meier survival analysis. Implants were grouped by surface type, and the cumulative hazard functions of total complication cases were compared. The biomechanical properties of the BellaGel implant and other company representative implants were tested using a mechanical testing machine, and surface topography was analyzed using a 3D laser scanning confocal microscope. There was a significant difference in the incidence of complications between the reconstruction (17.1%) and augmentation (4.7%) groups, but no significant difference in the complication rates of each group. There was no difference in the reoperation or revision rates between the groups. The log rank test showed a statistically significant difference in cumulative hazard function between the groups. Among the three types of implants (smooth, textured, and microtextured), the microtextured type had the lowest complication rate. The BellaGel microtexture implant had the highest maximal tensile load and displacement value. The BellaGel and Silksurface implants had the highest stored energy, although there was no significant difference. BellaGel implants can serve as a criterion for the selection of safe and effective implants among currently available implants.

Amine Modification of Silica Aerogels/Xerogels for Removal of Relevant Environmental Pollutants.

Serious environmental and health problems arise from the everyday release of industrial wastewater effluents. A wide range of pollutants, such as volatile organic compounds, heavy metals or textile dyes, may be efficiently removed by silica materials advanced solutions such as aerogels. This option is related to their exceptional characteristics that favors the adsorption of different contaminants. The aerogels performance can be selectively tuned by an appropriate chemical or physical modification of the aerogel's surface. Therefore, the introduction of amine groups enhances the affinity between different organic and inorganic contaminants and the silica aerogels. In this work, different case studies are reported to investigate and better understand the role of these functional groups in the adsorption process, since the properties of the synthesized aerogels were significantly affected, regarding their microstructure and surface area. In general, an improvement of the removal efficiency after functionalization of aerogels with amine groups was found, with removal efficiencies higher than 90% for lead and Rubi Levafix CA. To explain the adsorption mechanism, both Langmuir and Freundlich models were applied; chemisorption is most likely the sorption type taking place in the studied cases.

Microwave Assisted Sol-Gel Synthesis of Silica-Spider Silk Composites.

This study introduces a simple and environmentally friendly method to synthesize silica-protein nanocomposite materials using microwave energy to solubilize hydrophobic protein in an aqueous solution of pre-hydrolyzed organo- or fluoro-silane. Sol-gel functionality can be enhanced through biomacromolecule incorporation to tune mechanical properties, surface energy, and biocompatibility. Here, synthetic spider silk protein and organo- and fluoro-silane precursors were dissolved and mixed in weakly acidic aqueous solution using microwave technology. Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) images revealed the formation of spherical nanoparticles with sizes ranging from 100 to 500 nm depending, in part, on silane fluoro- or organo-side chain chemistry. The silane-protein interaction in the nanocomposite was assessed through infrared spectroscopy. Deconvoluted ATR-FTIR (Attenuated total reflectance Fourier-transform infrared spectroscopy) spectra revealed silane chemistry-specific conformational changes in the protein-silane nanocomposites. Relative to microwave-solubilized spider silk protein, the ß structure content increased by 14% in the spider silk-organo-silica nanocomposites, but decreased by a net 20% in the spider silk-fluoro-silica nanocomposites. Methods of tuning the secondary structures, and in particular ß-sheets that are the cross-linking moieties in spider silks and other self-assembling fibrillar proteins, may provide a unique means to promote protein interactions, favor subsequent epitaxial growth process, and enhance the properties of the protein-silane nanocomposites.

Fabrication and Characterization of MSQ Aerogel Coating on ePTFE Thin Films for Cable Sheaths.

With methylsilsesquioxane (MSQ) aerogels synthesized by the sol-gel method as a raw material and Si-Ti sol as a binder, an alcohol-based aerogel slurry consisting of only MSQ aerogel and Si-Ti sol was prepared and coated on expanded polytetrafluoroethylene (ePTFE) to form an MSQ aerogel coating layer, followed by low-temperature heat treatment. The effect of Si-Ti sol content on the microstructure of the MSQ aerogel coating layer was investigated, and the properties of a typical MSQ aerogel-layer-coated ePTFE film were evaluated. The results show that Si-Ti sol has an important role in terms of film-forming capability, surface smoothness, flexibility, and powder dropping of the MSQ aerogel coating layer. With a Si-Ti sol of 10.5 wt.% content as a binder and after heat treatment at 170 °C for 30 min, the coated ePTFE flexible thin film with a layer thickness of 30 µm shows high uniformity, integrity, and electrical insulation properties, with an elongation at break decrease over 130%, a thermal conductivity of 0.1753 W/(m·K) at 25 °C, a dielectric constant of 16.5674, and a dielectric loss of 0.06369, which can be promisingly applied in cable sheaths.

Theories of Etiopathogenesis of Breast Implant-Associated Anaplastic Large Cell Lymphoma.

Breast implant-associated anaplastic large cell lymphoma is a malignancy of T lymphocytes that is associated with the use of textured breast implants in both esthetic and reconstructive surgeries. Patients typically present with a delayed seroma 8-10 years following implantation or-less commonly-with a capsular mass or systemic disease. Current theories on disease pathogenesis focus on the interplay among textured implants, Gram-negative bacteria, host genetics, and time. The possible roles of silicone leachables and particles have been less well substantiated. This review aims to synthesize the existing scientific evidence regarding breast implant-associated anaplastic large cell lymphoma etiopathogenesis.

Breast Implant Illness: A Way Forward.

The link between breast implants and systemic disease has been reported since the 1960s. Although many studies have looked at either supporting or refuting its existence, the issue still persists and has now been labeled "breast implant illness." The rise of patient advocacy and communication through social media has led to an increasing number of presentations to plastic surgeons. This article summarizes the history of breast implants and systemic disease, critically analyzes the literature (and any associated deficiencies), and suggests a way forward through systematic scientific study.

Physical Properties of Silicone Gel Breast Implants.

BACKGROUND: Surgical applications using breast implants are individualized operations to fill and shape the breast. Physical properties beyond shape, size, and surface texture are important considerations during implant selection. OBJECTIVES: Compare form stability, gel material properties, and shell thickness of textured shaped, textured round, and smooth round breast implants from 4 manufacturers: Allergan, Mentor, Sientra, and Establishment Labs, through bench testing. METHODS: Using a mandrel height gauge, form stability was measured by retention of dimensions on device movement from a horizontal to vertical supported orientation. Dynamic response of the gel material (gel cohesivity, resistance to gel deformation, energy absorption) was measured using a synchronized target laser following application of graded negative pressure. Shell thickness was measured using digital thickness gauge calipers. RESULTS: Form stability, gel material properties, and shell thickness differed across breast implants. Of textured shaped devices, Allergan Natrelle 410 exhibited greater form stability than Mentor MemoryShape and Sientra Shaped implants. Allergan Inspira round implants containing TruForm 3 gel had greater form stability, higher gel cohesivity, greater resistance to gel deformation, and lower energy absorption than those containing TruForm 2 gel and in turn, implants containing TruForm 1 gel. Shell thickness was greater for textured vs smooth devices, and differed across styles. CONCLUSIONS: Gel cohesivity, resistance to gel deformation, and energy absorption are directly related to form stability, which in turn determines shape retention. These characteristics provide information to aid surgeons choosing an implant based on surgical application, patient tissue characteristics, and desired outcome.

Ultrasoft Silicone Gel as a Biomimetic Passivation Layer in Inkjet-Printed 3D MEA Devices.

Multielectrode arrays (MEAs) are versatile tools that are used for chronic recording and stimulation of neural cells and tissues. Driven by the recent progress in understanding of how neuronal growth and function respond to scaffold stiffness, development of MEAs with a soft cell-to-device interface has gained importance not only for in vivo but also for in vitro applications. However, the passivation layer, which constitutes the majority of the cell-device interface, is typically prepared with stiff materials. Herein, a fabrication of an MEA device with an ultrasoft passivation layer is described, which takes advantage of inkjet printing and a polydimethylsiloxane (PDMS) gel with a stiffness comparable to that of the brain. The major challenge in using the PDMS gel is that it cannot be patterned to expose the sensing area of the electrode. This issue is resolved by printing 3D micropillars at the electrode tip. Primary cortical neurons are grown on the fabricated device, and effective stimulation of the culture confirms functional cell-device coupling. The 3D MEA device with an ultrasoft interface provides a novel platform for investigating evoked activity and drug responses of living neuronal networks cultured in a biomimetic environment for both fundamental research and pharmaceutical applications.

Cost-Effectiveness Analysis of Silicone versus Saline Implant-Based Breast Reconstruction Using the BREAST-Q.

BACKGROUND: The most common type of breast reconstruction is implant-based breast reconstruction. Implant-based reconstruction has been reported to impact quality-of-life outcomes. Therefore, the authors sought to evaluate the cost-effectiveness of saline versus silicone implants. METHODS: The authors retrospectively reviewed data from patients who underwent breast reconstruction with saline or silicone implants at their institution. This included type of procedure, acellular dermal matrix use, complications, and number of revisions. Costs were estimated using the Centers for Medicare and Medicaid Services physician fee schedule and hospital costs. Effectiveness was measured using BREAST-Q-adjusted life-years, a measure of years of perfect breast health, based on BREAST-Q data collected before mastectomy and reconstruction and at 12 months after final reconstruction. The incremental cost-effectiveness ratio was obtained for silicone and saline reconstruction. RESULTS: The authors identified 134 women, among which 77 (57 percent) underwent silicone and 57 (43 percent) underwent saline breast reconstruction. The cost of saline reconstruction was $1288.23 less compared with silicone. BREAST-Q-adjusted life-years were 28.11 for saline and 23.57 for silicone, demonstrating higher cost-effectiveness for saline. The incremental cost-effectiveness ratio for saline was -$283.48, or $283.48 less per year of perfect breast-related health postreconstruction than silicone. CONCLUSIONS: The authors' results indicate that saline breast reconstruction may be more cost-effective compared with silicone at 12 months after final reconstruction. Silicone was both more expensive and less effective than saline. However, given the relatively small cost difference, surgeon and patient preference may be important in determining type of implant used.

Large-Scale Preparation of Giant Vesicles by Squeezing a Lipid-Coated Marshmallow-like Silicone Gel in a Buffer.

Giant vesicles were efficiently produced by squeezing a lipid (l-α-phosphatidylcholine from egg yolk)-coated marshmallow-like flexible macroporous silicone monolith in a buffer. The mean diameter of the obtained vesicles was 2 µm, showing a wide distribution, up to tens of micrometers, which was similar to that of vesicles formed by a natural swelling method. It was possible to prepare vesicle dispersions on a scale from several microliters to several hundred milliliters. A protein synthesis system (PURE system) contained in vesicles prepared using this method functioned effectively. Our absorbing-squeezing method is expected to help in studies that use giant vesicles such as artificial cells and drug delivery systems.

Desmoid Tumor and Silicone Breast Implant Surgery: Is There Really a Connection? A Literature Review.

BACKGROUND: Desmoid tumors are borderline tumors of the connective tissue, arising in the musculo-aponeurotic stromal elements. A desmoid tumor (DT) has an infiltrative and locally aggressive growth pattern and usually does not metastasize; however, it has a high recurrence and complication rate. DT located in the breast (BDT) represents a rare extra-abdominal form. Recently, the presence of breast silicone implants was suggested by several researchers as a risk factor for developing BDT. OBJECTIVES: The goal of this review is to investigate the possible correlation between BDT and breast implant surgery. METHODS: We conducted a literature review of BDT-reported cases, associated with breast implant surgery. RESULTS: The search revealed 36 cases of BDT associated with silicone breast implants. CONCLUSIONS: Based on the reviewed data, the incidence of BDT following breast implant surgery is lower than BDT in the general population. At the moment, a possible association between breast implants and the development of breast desmoid tumors cannot be unequivocally confirmed. A world registry with accurate documentation of each case of BDT associated with breast implant surgery should be performed for future investigation. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Preliminary 3-Year Evaluation of Experience With SilkSurface and VelvetSurface Motiva Silicone Breast Implants: A Single-Center Experience With 5813 Consecutive Breast Augmentation Cases.

BACKGROUND: Silicone breast implants have been in use for breast augmentation for more than 50 years, but technological innovation has been lacking in implant design until recently. OBJECTIVES: This study was designed to evaluate the complication and reoperation rates following breast augmentation utilizing the Motiva silicone breast implants. METHODS: This retrospective study evaluated the safety of Motiva implants in 5813 consecutive cases of breast augmentation. Implants with two different textured surfaces were evaluated: SilkSurface (nanotextured) and VelvetSurface (micro-textured). RESULTS: Implants were placed between April 2013 and April 2016. A total of 44 complications were reported, with an overall complication rate of 0.76%, and the rate of reoperation was 0.76% over an interval of 3 years. There were no late complications and no cases of primary capsular contracture. No differences in complication rates were observed because of the implant date. However, among patients who received implants 300 to 499 cc in volume, complication rates were significantly lower with SilkSurface compared with VelvetSurface implants. Advanced statistical analysis supported the validity of the low complication rate reported in this study. CONCLUSIONS: Overall, these findings suggest that Motiva silicone breast implants are associated with very low rates of complication and reoperation, and that the nano-textured SilkSurface implant is associated with fewer complications than micro-textured implants.

Compatibility of phospholipid liposomal spray with silicone hydrogel contact lens wear.

PURPOSE: To assess the effects of two weeks of regular phospholipid liposomal spray application on lipid layer grade, tear film stability, subjective comfort, visual acuity, and lipid deposition in silicone hydrogel contact lens wearers. METHODS: Thirty-one existing contact lens wearers were enrolled and fitted with two week planned replacement silicone hydrogel contact lenses (Acuvue® Oasys®) in a prospective, randomized, paired-eye, investigator-masked trial. A phospholipid liposomal spray (Tears Again®) was applied to one eye (randomized) four times daily for two weeks. LogMAR high contrast visual acuity (VA), low contrast glare acuity (LCGA), non-invasive tear film break-up time (NIBUT), and lipid layer grade (LLG) were measured at baseline and day 14, in both treated and control eyes. Subjective comfort relative to baseline, and spectrofluorophotometric assessment of contact lens surface lipid deposition were also assessed on day 14. RESULTS: All measurements did not differ at baseline between treated and control eyes. Lipid layer thickness and tear film stability were increased on day 14 in treated eyes (all p<0.05), but not in control eyes (all p>0.05). A greater proportion of participants reported improved comfort in the treated eye relative to the control eye (p=0.002). There were no significant differences in visual acuity or in contact lens surface lipid deposition, between treated and control eyes, on day 14 (all p>0.05). CONCLUSION: The phospholipid liposomal spray increased tear film stability, lipid layer thickness and subjective comfort in silicone hydrogel contact lens wearers, without adversely affecting visual acuity or contact lens surface lipid deposition.

The impact of lens care solutions on corneal epithelial changes during daily silicone hydrogel contact lens wear as measured by in vivo confocal microscopy.

PURPOSE: To assess corneal epithelial microstructure via confocal microscopy and determine if cellular changes are associated with lens care solutions during daily wear of silicone hydrogel contact lenses. METHODS: Corneal in vivo confocal microscopy with the Nidek ConfoScan4 was performed at baseline and after 5 months of lotrafilcon A daily contact lens wear. Enrolled participants were randomized to use either a polyhexamethylene biguanide (PHMB) preserved multipurpose care solution (MPS) or a peroxide based solution system. Lens and storage case bioburden were assessed with aerobic culture methods. Univariate and multivariable analyses were done to evaluate the association between solution use, or solution-related clinical covariates, and morphologic differences (hyper-reflectivity) in the superficial epithelial cells and epithelial basal cell density. RESULTS: Data on 139 participants were available for analysis of superficial epithelial cells while data on 92 participants were available for epithelial basal cell density. Five months after randomization to the solution groups, 33% of participants had visible hyper-reflective cells. More participants using MPS had ≥1 hyper-reflective cells compared to peroxide users at 5 months (44% vs. 22%; p=0.006). Similarly at 5 months, more participants with solution-induced corneal staining (SICS) had ≥1 hyper-reflective cells compared to non-SICS participants (57% vs. 29%; p=0.010). The adjusted odds ratios (ORs) for risk of presenting with hyper-reflective cells in MPS users or SICS participants was 2.7 (95% CI; 1.27-5.65) and 3.4 (95% CI; 1.29-8.97), respectively. Basal cell density decreased by over 350 cells/mm2 over time (about 6%) in participants who had substantial bioburden on their lenses or in their storage case. CONCLUSION: The confocal microscope can detect epithelial cellular changes in vivo during contact lens wear. Hyper-reflective superficial epithelial cells are associated with a PHMB preserved solution and decreases in basal epithelial cell density may be associated with bacterial bioburden.

Synthesis and characterization of nanosilver-silicone hydrogel composites for inhibition of bacteria growth.

PURPOSE: Nanosilver-silicone hydrogel (NAgSiH) composites for contact lenses were synthesized to asses the antimicrobial effects. METHODS: Silicone hydrogel (SiH) films were synthesized followed by impregnation in silver nitrate solutions (10, 20, 30, 40, 60, 80ppm) and in-situ chemical reduction of silver ions using sodium borohydride (NaBH4). The silver nano particles (AgNPS) were identified by UV-vis absorption spectroscopy, Energy-dispersive X-ray spectroscopy (EDX) mapping and EDX spectrum. Physico-mechanical and chemical properties of NAgSIH films were studied. The antimicrobial effect of the hydrogels against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus was evaluated. The numbers of viable bacterial cells on NAgSiH surface or in solution compared to control SiH were examined. RESULTS: The NAgSiH films were successfully synthesized. FTIR results indicated that AgNPS had no effect on the bulk structure of the prepared SiH films. From TGA analysis, NAgSiH(R80) and SiH(R0) films had the same maximum decomposition temperature (404°C). UV-vis absorption spectroscopy and EDX mapping and spectrum emphasized that AgNPS were in spherical shape. The maximum absorption wavelength of NAgSiH films were around 400nm. The light transmittance decreased as the concentration of AgNPS increased, but still greater than 90% at wavelength around 555nm. The Young's modulus increased gradually from 1.06MPa of SiH(R0) to highest value 1.38MPa of NAgSiH(R80). AgNPS incorporated into SiH films reduced the bacterial cell growth and prevented colonization. Groups NAgSiH(R60,R80) demonstrated an excellent reduction in bacterial viability in solution and on the SiH surface. CONCLUSIONS: NAgSiH composites were successfully synthesized and possessed an excellent antimicrobial effects.

Simvastatin Reduces Capsular Fibrosis around Silicone Implants.

Capsular fibrosis and contracture occurs in most breast reconstruction patients who undergo radiotherapy, and there is no definitive solution for its prevention. Simvastatin was effective at reducing fibrosis in various models. Peri-implant capsular formation is the result of tissue fibrosis development in irradiated breasts. The purpose of this study was to examine the effect of simvastatin on peri-implant fibrosis in rats. Eighteen male Sprague-Dawley rats were allocated to an experimental group (9 rats, 18 implants) or a control group (9 rats, 18 implants). Two hemispherical silicone implants, 10 mm in diameter, were inserted in subpanniculus pockets in each rat. The next day, 10-Gy of radiation from a clinical accelerator was targeted at the implants. Simvastatin (15 mg/kg/day) was administered by oral gavage in the experimental group, while animals in the control group received water. At 12 weeks post-implantation, peri-implant capsules were harvested and examined histologically and by real-time polymerase chain reaction. The average capsular thickness was 371.2 µm in the simvastatin group and 491.2 µm in the control group. The fibrosis ratio was significantly different, with 32.33% in the simvastatin group and 58.44% in the control group (P < 0.001). Connective tissue growth factor (CTGF) and transforming growth factor (TGF)-ß1 gene expression decreased significantly in the simvastatin group compared to the control group (P < 0.001). This study shows that simvastatin reduces radiation-induced capsular fibrosis around silicone implants in rats. This finding offers an alternative therapeutic strategy for reducing capsular fibrosis and contracture after implant-based breast reconstruction.

Effect of multipurpose solutions on in vivo surface wettability of a silicone hydrogel lens.

PURPOSE: To compare the in vivo surface wettability of silicone hydrogel (SiHy) contact lenses pre-soaked overnight in different multipurpose solutions (MPS) and normal saline. METHODS: In this double-blinded, randomized and self-controlled study, 36 subjects were fitted with three pairs of contact lenses (senofilcon A) pre-soaked overnight in five different MPS and saline in a randomized order. Each pair of lenses (pre-soaked in two different solutions the night before) were worn for 15min before assessment of pre-lens non-invasive tear break-up time (PL-NITBUT) using the Medmont corneal topographer (video recording). Corneal integrity was assessed using a slit lamp and a resting interval of 20min was allowed between each pair of lenses to ensure post-lens wear corneal integrity. RESULTS: Thirty subjects completed the study. The median PL-NITBUT ranged from 2.84s to 3.08s with lenses pre-soaked in different MPS, compared to 2.78s with lenses pre-soaked in saline. No significant differences in PL-NITBUT were found among lenses pre-soaked in different solutions (p=0.647). CONCLUSION: In vivo surface wettability, in terms of PL-NITBUT after 15min of lens wear, of senofilcon A contact lenses pre-soaked overnight in different MPS were not significantly different from those pre-soaked in saline.