In Vivo Release of Zafirlukast from Electrospun Polyisobutylene-Based Fiber Mats to Reduce Capsular Contracture of Silicone Breast Prostheses.

Silicone rubber tissue expanders and breast implants are associated with chronic inflammation, leading to the formation of fibrous capsules. If the inflammation is left untreated, the fibrous capsules can become hard and brittle and lead to formation of capsular contracture. When capsular contracture occurs, implant failure and reoperation is unavoidable. Fibrous capsule formation to medical grade silicone rubber breast implants and polyisobutylene-based electrospun fiber mats attached to silicone rubber with and without an anti-inflammatory therapeutic were compared. A linear polyisobutylene (PIB)-based thermoplastic elastomer is currently applied as a polymer coating for drug release on coronary stents to reduce restenosis. Recent work has created a drug releasing electrospun fiber mat from PIB-based materials. Important to this study, poly(alloocimene-b-isobutylene-b-alloocimene) (AIBA) was electrospun with zafirlukast (ZAF). ZAF is an anti-inflammatory drug that is able to reduce capsule formation and complications to silicone breast implants. Fiber mats are advantageous for local drug delivery because of their high porosity and surface area for drug release. The chief hypothesis was that local release of ZAF from AIBA would lower inflammatory signaling and resulting capsular formation after 90 days in vivo. Electrospun AIBA mats locally released ZAF, lowering inflammation and fibrous capsule development compared to medical grade silicone rubber. Locally and orally released ZAF led to similar results, but the former had much lower concentration that highlights local delivery's therapeutic potential. Released ZAF from AIBA fiber mats mitigated inflammation and serves as an alternative to existing clinical approaches.

Using Digestion by IdeS Protease to Improve Quantification of Degradants in Monoclonal Antibodies by Non-Reducing Capillary Gel Electrophoresis.

Monoclonal antibodies (mAbs) have become predominant therapeutics by providing highly specific mechanisms of action enabling treatment of complex diseases. However, mAbs themselves are highly complex and require thorough testing and characterization to ensure efficacy and patient safety. In this regard, fragmentation is a degradation product of concern. The biotechnology industry uses capillary gel electrophoresis (CGE) to quantify fragmentation by electrophoretically resolving size variants, such as products resulting from partial reduction of interchain disulfides. However, standard CGE methods may not adequately separate less typical fragments, particularly when there is minimal size difference to the parent molecule. For mAb-1, a degradant only ∼11 kDa smaller than the intact mAb (∼149 kDa) was unable to be resolved under typical non-reducing conditions, preventing an accurate purity assessment and precluding tracking of product purity within stability studies. To address these deficiencies, a subunit-based non-reducing CGE method was developed to employ IdeS protease to produce F(ab')2 and Fc fragments, which resulted in baseline resolution of the clipped subunit species from its parent species. This enabled more accurate trending of purity throughout stability studies. Method characterization ensured that this subunit method monitored expected impurities observed by intact non-reducing CGE and thus could suitably replace non-reducing CGE in the release and stability testing panel. It also has the potential to replace reducing CGE based on its tracking of the deglycosylated Fc species. We believe this approach of utilizing proteases to develop subunit CGE methods for release and stability can be applied to other molecules when in need of resolving analogous fragments.

Optimizing Rapid Sequence Intubation for Medical and Trauma Patients in the Pediatric Emergency Department.

INTRODUCTION: Rapid sequence intubation (RSI) is a critical procedure for severely ill and injured patients presenting to the pediatric emergency department (PED). This procedure has a high risk of complications, and multiple attempts increase this risk. We aimed to increase successful intubation within two attempts, focusing on medical and trauma patients separately to identify improvement barriers for each group. METHODS: A multifaceted intervention was implemented using quality improvement methods. The analysis included adherence to the standardized process, successful intubation within two attempts, and frequency of oxygen saturations <92% during laryngoscopy. Trauma and medical patients were analyzed separately as team composition differed for each. RESULTS: This project began in February 2018, and we included 290 patients between April 2018 and December 2019. Adherence to the standardized process was sustained at 91% for medical patients and a baseline of 55% for trauma patients with a trend toward improvement. In May 2018, we observed and sustained special cause variations for medical patients' successful intubations within two attempts (77-89%). In September 2018, special cause variation was observed and sustained for the successful intubation of trauma patients within two attempts (89-96%). The frequency of oxygen saturation of <92% was 21% for medical patients; only one trauma patient experienced oxygen desaturation. CONCLUSION: Implementation of a standardized process significantly improved successful intubations within two attempts for medical and trauma patients. Trauma teams had more gradual adherence to the standardized process, which may be related to the relative infrequency of intubations and variable team composition.

Architectured helically coiled scaffolds from elastomeric poly(butylene succinate) (PBS) copolyester via wet electrospinning.

Electrospinning is one of the most investigated methods used to produce polymeric fiber scaffolds that mimic the morphology of native extracellular matrix. These structures have been extensively studied in the context of scaffolds for tissue regeneration. However, the compactness of materials obtained by traditional electrospinning, collected as two-dimensional non-woven scaffolds, can limit cell infiltration and tissue ingrowth. In addition, for applications in smooth muscle tissue engineering, highly elastic scaffolds capable of withstanding cyclic mechanical strains without suffering significant permanent deformations are preferred. In order to address these challenges, we report the fabrication of microscale 3D helically coiled scaffolds (referred as 3D-HCS) by wet-electrospinning method, a modification of the traditional electrospinning process in which a coagulation bath (non-solvent system for the electrospun material) is used as the collector. The present study, for the first time, successfully demonstrates the feasibility of using this method to produce various architectures of 3D helically coiled scaffolds (HCS) from segmented copolyester of poly (butylene succinate-co-dilinoleic succinate) (PBS-DLS), a thermoplastic elastomer. We examined the role of process parameters and propose a mechanism for the HCS formation. Fabricated 3D-HCS showed high specific surface area, high porosity, and good elasticity. Further, the marked increase in cell proliferation on 3D-HCS confirmed the suitability of these materials as scaffolds for soft tissue engineering.

The effect of four different freezing conditions and time in frozen storage on the concentration of commonly measured growth factors and enzymes in equine platelet-rich plasma over six months.

BACKGROUND: Platelet-rich plasma (PRP) is a therapeutic biologic that is used for treatment of musculoskeletal pathologies in equine athletes. Due to the expense of PRP kits, and the volumes obtained, freezing aliquots for future dosing is common. Aliquots of PRP are also commonly frozen for later analysis of growth factor concentrations in in vitro research. A variety of freezing methods are used and storage duration until analysis is often not reported. The optimal frozen storage conditions and duration to maintain concentrations of commonly measured growth factors and enzymes in PRP are unknown. Our objectives were two-fold. First, to determine the effect of a single freeze-thaw cycle on PRP protein concentrations and establish their baseline levels. Second, to evaluate the effect of storage in -20 °C automatic defrost freezer, - 20 °C manual defrost freezer, - 80 °C manual defrost freezer, and liquid nitrogen for 1, 3, and 6 months on PRP protein concentrations, compared to the established baseline concentrations. RESULTS: Fold-change between fresh activated and snap frozen PRP were analyzed using paired t-test. A snap frozen-thaw cycle resulted in increased MMP-9 (p = 0.0021), and a small significant decrease in TGF-ß1 (p = 0.0162), while IGF-1 and PDGF-BB were unchanged compared to fresh activated PRP. Fold-change over time within storage method were analyzed using repeated measures ANOVA and Tukey post-hoc test. IGF-1 decreased in all conditions (p < 0.0001). At all time-points at -20 °C (p < 0.0001), and at 3 and 6 months at -80 °C (p < 0.0070), PDGF-BB decreased. TGF- ß1 was unchanged or increased after 6 months (p < 0.0085). MMP-9 decreased at 3-months at -20 °C, and at all times at -80 °C and in liquid nitrogen compared to snap frozen (p < 0.0001). CONCLUSIONS: The protein profile of equine frozen-stored PRP differs from fresh PRP. For clinical applications equine PRP can be stored at -80 °C for 1 month or in liquid nitrogen for 6 months to maintain PDGF-BB and TGF-ß1 concentration, but IGF-1 concentrations will be reduced. The storage temperature and duration should be reported in studies measuring protein concentrations in PRP. To accurately measure IGF-1 concentrations, PRP samples should be analyzed immediately.

Folic acid conjugated polymeric drug delivery vehicle for targeted cancer detection in hepatocellular carcinoma.

Targeted therapies provide increased efficiency for the detection and treatment of cancer with reduced side effects. Folate receptor (alpha subunit) is overexpressed in multiple tumors including liver cancer. In this study, we evaluated the specificity and toxicity of a folic acid-containing drug delivery vehicle (DDV) in a hepatocellular carcinoma (HCC) model. The DDV was prepared with two units each of folic acid (FA) and fluorescein isothiocyanate (FITC) molecules and conjugated to a central poly (ethylene glycol) (PEG) core via a modified chemo-enzymatic synthetic process. Rat hepatoma (N1S1) and human monocytic (U937) cell lines were used for cell culture-based assays and tested for DDV uptake and toxicity. Folate receptor expressions in liver tissues and cell lines were verified using standard immunohistochemistry techniques. Rat HCC model was used for in vivo assessment. The DDV was injected via intra-arterial or intravenous methods and imaged with IVIS spectrum in vivo imaging system. Strong signals of FITC in the liver tumor region correlated to targeted DDV uptake. The use of PEG enhanced water-solubility and provided flexibility for the interaction of FA ligands with multiple cell surface folate receptors that resulted in increased specific uptake. Our study suggested that PEG incorporation and folate targeting via intra-arterial approach is an efficient strategy for targeted delivery in HCC therapy.

Enzymatic Degradation of Poly(butylene succinate) Copolyesters Synthesized with the Use of Candida antarctica Lipase B.

Biodegradable polymers are an active area of investigation, particularly ones that can be produced from sustainable, biobased monomers, such as copolymers of poly(butylene succinate) (PBS). In this study, we examine the enzymatic degradation of poly(butylene succinate-dilinoleic succinate) (PBS-DLS) copolymers obtained by "green" enzymatic synthesis using lipase B from Candida antarctica (CALB). The copolymers differed in their hard to soft segments ratio, from 70:30 to 50:50 wt %. Enzymatic degradation was carried out on electrospun membranes (scaffolds) and compression-moulded films using lipase from Pseudomomas cepacia. Poly(ε-caprolactone) (PCL) was used as a reference aliphatic polyester. The degradation process was monitored gravimetrically via water uptake and mass loss. After 24 days, approx. 40% mass loss was observed for fibrous materials prepared from the PBS-DLS 70:30 copolymer, as compared to approx. 10% mass loss for PBS-DLS 50:50. Infrared spectroscopy (FTIR) and size exclusion chromatography (SEC) analysis were used to examine changes in chemical structure. Differential scanning calorimetry (DSC) and scanning light microscopy (LSM) revealed changes in degree of crystallinity, and changes in surface morphology, consistent with a surface erosion mechanism. We conclude that the obtained copolymers are suitable for tissue engineering applications thanks to tuneable degradation and lack of acidification during breakdown.