Generating Lifetime-Enhanced Microbubbles by Decorating Shells with Silicon Quantum Nano-Dots Using a 3-Series T-Junction Microfluidic Device

Long-term stability of microbubbles is crucial to their effectiveness. Using a new microfluidic device connecting three T-junction channels of 100 μm in series, stable monodisperse SiQD-loaded bovine serum albumin (BSA) protein microbubbles down to 22.8 ± 1.4 μm in diameter were generated. Fluorescence microscopy confirmed the integration of SiQD on the microbubble surface, which retained the same morphology as those without SiQD. The microbubble diameter and stability in air were manipulated through appropriate selection of T-junction numbers, capillary diameter, liquid flow rate, and BSA and SiQD concentrations. A predictive computational model was developed from the experimental data, and the number of T-junctions was incorporated into this model as one of the variables. It was illustrated that the diameter of the monodisperse microbubbles generated can be tailored by combining up to three T-junctions in series, while the operating parameters were kept constant. Computational modeling of microbubble diameter and stability agreed with experimental data. The lifetime of microbubbles increased with increasing T-junction number and higher concentrations of BSA and SiQD. The present research sheds light on a potential new route employing SiQD and triple T-junctions to form stable, monodisperse, multi-layered, and well-characterized protein and quantum dot-loaded protein microbubbles with enhanced stability for the first time

Assessment of electromechanically stimulated bone marrow stem cells seeded acellular cardiac patch in a rat myocardial infarct model

In this study, we evaluated cardiomyogenic differentiation of electromechanically stimulated rat bone marrow-derived stem cells (rt-BMSCs) on an acellular bovine pericardium (aBP) and we looked at the functioning of this engineered patch in a rat myocardial infarct (MI) model. aBP was prepared using a detergent-based decellularization procedure followed by rt-BMSCs seeding, and electrical, mechanical, or electromechanical stimulations (3 millisecond pulses of 5 V cm-1at 1 Hz, 5% stretching) to enhance cardiomyogenic differentiation. Furthermore, the electromechanically stimulated patch was applied to the MI region over 3 weeks. After this period, the retrieved patch and infarct region were evaluated for the presence of calcification, inflammatory reaction (CD68), patch to host tissue cell migration, and structural sarcomere protein expressions. In conjunction with any sign of calcification, a higher number of BrdU-labelled cells, and a low level of CD68 positive cells were observed in the infarct region under electromechanically stimulated conditions compared with static conditions. More importantly, MHC, SAC, Troponin T, and N-cad positive cells were observed in both infarct region, and retrieved engineered patch after 3 weeks. In a clear alignment with other results, our developed acellular patch promoted the expression of cardiomyogenic differentiation factors under electromechanical stimulation. Our engineered patch showed a successful integration with the host tissue followed by the cell migration to the infarct region

Synthesis of Emulsion-Templated Acrylic-Based Porous Polymers: From Brittle to Elastomeric

High internal phase emulsion polymers (PolyHIPEs) are novel materials that have high porosity and interconnected open-cell structure and are used in various applications such as supports for catalytic systems, media for separation of similar molecules, and scaffolds for tissue engineering. In this study, 90% porous acrylic based polyHIPE structures with various cellular structure and mechanical characteristics were developed by using stearyl acrylate (SA), isodecyl acrylate (IDA), isobornyl methacrylate (IBMA), and divinylbenzene (DVB). Elastomeric polyHIPEs were produced from the comonomers of SA and IDA, and had high ability of recovery when the applied stress was removed. IBMA based polyHIPEs were brittle and demonstrated higher Young's modulus and compression strength than that of conventional styrene based polyHIPEs at the same void volume. Therefore, by varying the composition, it became possible to alter the mechanical properties of polyHIPEs from brittle to elastomeric, without changing the interconnected cellular structures

Oligonucleotide-Based Theranostic Nanoparticles In Cancer Therapy

Theranostic approaches, combining the functionality of both therapy and imaging, have shown potential in cancer nanomedicine. Oligonucleotides such as small interfering RNA and microRNA, which are powerful therapeutic agents, have been effectively employed in theranostic systems against various cancers. Nanoparticles are used to deliver oligonucleotides into tumors by passive or active targeting while protecting the oligonucleotides from nucleases in the extracellular environment. The use of quantum dots, iron oxide nanoparticles and gold nanoparticles and tagging with contrast agents, like fluorescent dyes, optical or magnetic agents and various radioisotopes, has facilitated early detection of tumors and evaluation of therapeutic efficacy. In this article, we review the advantages of theranostic applications in cancer therapy and imaging, with special attention to oligonucleotide-based therapeutics.Wo

A scoping review of tissue interposition flaps used in vesicovaginal fistulae repair

Background: Research on the use of tissue interposition flaps (TIFs) in vesicovaginal fistulae (VVF) repair is a broad area where a very wide range of natural and synthetic materials have been used. The occurrence of VVF is also diverse in the social and clinical settings, resulting in a parallel heterogeneity in the published literature on its treatment. The use of synthetic and autologous TIFs in VVF repair is not yet standardized with a lack of the most efficacious type and technique of the TIF. Objectives: The aim of this study was to systematically review all synthetic and autologous TIFs used in the surgical repair of VVFs. Data sources and methods: In this scoping review, the surgical outcomes of autologous and synthetic interposition flaps used in VVF treatment meeting the inclusion criteria were determined. We searched the literature using Ovid MEDLINE and PubMed databases between 1974 and 2022. Study characteristics were recorded, and data on the change in fistulae size and location, surgical approach, success rate, preoperative patient evaluation and outcome evaluation were extracted from each study independently by two authors. Results: A total of 25 articles that met the inclusion criteria were included in the final analysis. A total of 943 and 127 patients who had received autologous and synthetic flaps, respectively, were included in this scoping review. The fistulae characteristics were highly variable with regard to their size, complexity, aetiology, location and radiation. Outcome assessments of fistulae repair in included studies were mostly based on symptom evaluation. Physical examination, cystogram and methylene blue test were the methods in order of preference. Postoperative complications, such as infection, bleeding, donor site, pain, voiding dysfunction and other complications, were reported in patients after fistulae repair in all included studies. Conclusion: The use of TIFs in VVF repair was common especially in complex and large fistulae. Autologous TIFs appear to be the standard of care at the moment, and synthetic TIFs were investigated in prospective clinical trials in a limited number of selected cases. Evidence levels of clinical studies evaluating the effectiveness of interposition flaps were overall low

Brain targeting of Atorvastatin loaded amphiphilic PLGA-b-PEG nanoparticles

Eroglu, Hakan/0000-0001-6361-0074WOS: 000312505100002PubMed: 22734433The objective of this study was to develop polysorbate 80 coated and Atorvastatin loaded poly(lactic-co-glycolic acid)-block-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles and to investigate advantages of coating on nanoparticles for brain delivery of Atorvastatin. The nanoparticles were prepared by nanoprecipitation method. The effects of polymer concentration, PEG content and polysorbate 80 coating on the particle size, drug loading efficiency and release behaviour of nanoparticles were investigated. Additionally, cellular uptake and brain targeting of formulated nanoparticles were studied. Particle sizes were in the range of 30-172 nm depending on formulation parameters. Increasing the polymer concentration significantly increased the nanoparticle size. Decreasing the PEG content from 15% to 5% (w/w) in polymer composition increased the nanoparticle size from 69 to 172 nm. Both coated and uncoated polysorbate 80 nanoparticles were effectively internalised within the endothelial cells. Moreover, both types of nanoparticles were able to penetrate the blood brain barrier and reach the maximum in brain 1 h post injection. It was concluded that these nanoparticles are promising nanosystems for treatment of neurological disorders.Hacettepe University, Scientific Research UnitHacettepe University [07A301001]The authors would like to express their special thanks to the Metis Biotechnology Company for cooperation in in vivo imaging studies. This work was supported by grants from Hacettepe University, Scientific Research Unit (BAB, Grant no: 07A301001)

Comonomer effects on binding performances and morphology of acrylate-based imprinted polymers

The objective of this study was to investigate the effect of different functional groups of molecularly imprinted polymers (MIPs) on the binding characteristics towards a specific template molecule by examining selectivity and recognition processes. Several non-covalent theophylline imprinted polymers (TIPs) were prepared by using only methacrylic acid (MAA), or MAA and 2-hydroxyethyl methacrylate (HEMA) comonomer, or MAA and acrylamide (ACM) comonomer. In all cases, a high amount of ethylene glycol dimethacrylate (EDMA) as crosslinker existed in the medium. The highest selective theophylline binding of TIPs was found to be 61%, 41% and 40% for MAA/EDMA, MAA/HEMA/EDMA and MAA/ACM/EDMA systems, respectively. The use of a comonomer (ACM or HEMA) reduced the binding performance of the MAA/EDMA polymer matrix, probably due to the monomer-monomer association and morphological differences. Results obtained from the batch binding experiments demonstrated that all of the TIPs have sites that have selective binding ability for theophylline, but not to another structurally similar molecule, caffeine. According to the Langmuir isotherm model, a heterogeneous distribution of binding sites was observed in the polymers. The maximum association constant and binding site density were computed as 2.3 x 10(2) mM(-1) and 8.6 mu mol/g, respectively, for copolymer of MAA/EDMA under the examined concentration range