Investigating the influence of hydrophobicity on the thermoresponsive behavior of statistical copolymers

Thermoresponsive polymers have gained interest over many decades and have been used in diverse applications such as bioseparation, tissue engineering and drug delivery owing to their readily tunable nature. Several ways to tune the thermoresponsive behavior of polymers have been reported, providing a wide range of opportunities to design polymeric systems as required for specific applications. The aim of this project was to investigate the effect of polymer hydrophobicity on tuning the thermoresponsive behavior of statistical amphiphilic copolymers achieved via reversible addition-fragmentation chain-transfer (RAFT) polymerization and explore the biological efficacy of thermoresponsive nanoparticles functionalized with therapeutic moieties. Importantly, a computational tool was used for the determination of hydrophobicity of the produced copolymers, and it was aimed to correlate the values that represented polymer hydrophobicity to the measured macroscopic changes in the polymer solution upon change in temperature. The findings of these studies are expected to provide insight into the design of new functional copolymers with required thermoresponsiveness. Moreover, thermoresponsive nanoparticles were developed via polymerization-induced thermal self-assembly (PITSA) benefiting the versatile, easy applicable and robust nature of this technique. Functionalization of these nanoparticles with therapeutic synthetic peptides was achieved to explore the stability and of the nanoparticles. These studies are expected to contribute to future studies in creating functional drug delivery systems

Mechanistic Insights into Polymerization-Induced Self-Assembly Using Maleimide-Based Fluorophores

Polymerization-induced self-assembly (PISA) is a versatile and readily accessible method to produce nanoparticles of various morphologies in situ as polymerization progresses. PISA exploits the chain extension of a solvophilic macromolecular chain-transfer agent with monomers that are miscible in the continuous phase but form a solvophobic, immiscible polymer, driving self-assembly. However, the ability to monitor in situ the onset of self-assembly and the evolution of morphology during the PISA process remains a significant challenge, which critically limits our understanding of the mechanisms of particle formation. In this work, we demonstrate that a maleimide-based small-molecule fluorophore can act as a powerful probe to study PISA over time using fluorescence and fluorescence lifetime as outputs. We show that the aminochloromaleimide (ACM) fluorophore can be readily incorporated within a PISA system to produce fluorescent nanostructures without affecting their final morphology in comparison to their nonfluorescent analogues. The ACM probe exhibits diagnostic increases in fluorescence lifetime first with the onset of self-assembly and then with the evolution of particle morphology in the order of spheres > vesicles > worms. Excitingly, monitoring the change in fluorescence lifetime in situ during PISA yielded insights into the mechanism of particle formation when targeting higher-order morphologies. Finally, we demonstrate that these maleimide-functionalized nanostructures can be used as cell imaging agents using fluorescence lifetime imaging microscopy (FLIM), whereby each morphology produces distinct lifetime decay patterns within a cell environment. Overall, we envision this becoming a powerful tool for the analysis of nanoparticle states within complex environments, inspiring further investigations of the study of PISA using this simple and accessible method

Ovarian Ectopic Pregnancy in an Asymptomatic Patient

Ovarian pregnancy caused by the implantation of the fertilized ovum in the ovary is a rare type of ectopic pregnancy. In this study, our aim is to present an ovarian ectopic pregnancy case without any complaints except amenorrhea. A 34 year-old woman, gravida 2, para 1, was referred to our clinic with the diagnosis of ectopic pregnancy by the center which she had been admitted due to amenorrhea. She had no complaints and was clinically stable; however her pregnancy test was positive. Uterine bleeding was not observed and roughly 5 cm smooth edged and mobile right adnexal mass showing no tenderness with palpation was detected during pelvic examination. Transvaginal sonography showed that there was an endometrium in 25 mm thickness and there was no gestational sac. Left ovarian logy was normal, but an exitus embryo with a crown-rump length (CRL) measuring 11 mm (at 7 weeks, 2 days gestation) was detected on the right adnexal area. It was recorded that there was no fluid in the pouch of Douglas and the right ovary could not be distinguished. Laparoscopy was suggested and then laparoscopic right salpingo-oophorectomy was performed upon detection of ovarian pregnancy. Abdominal pain is the most frequent complaint in almost all ovarian ectopic pregnancy. Our patient is interesting because it is asymptomatic. The diagnosis of ovarian ectopic pregnancy is very difficult; patients may be asymptomatic and clinically stable. Ovarian ectopic pregnancy should be taken into consideration in the differential diagnosis of each ectopic pregnancy. The diagnosis is made surgically and histopathologically. Today, although laparoscopic conservative surgery is performed in the treatment, radical surgery may sometimes be required. [Cukurova Med J 2015; 40(Suppl 1): 42-46

Log P<sub style="">oct</sub>/SA predicts the thermoresponsive behavior of P(DMA-<i>co</i>-RA) statistical copolymers

[Image: see text] Polymers that exhibit a lower critical solution temperature (LCST) have been of great interest for various biological applications such as drug or gene delivery, controlled release systems, and biosensing. Tuning the LCST behavior through control over polymer composition (e.g., upon copolymerization of monomers with different hydrophobicity) is a widely used method, as the phase transition is greatly affected by the hydrophilic/hydrophobic balance of the copolymers. However, the lack of a general method that relates copolymer hydrophobicity to their temperature response leads to exhaustive experiments when seeking to obtain polymers with desired properties. This is particularly challenging when the target copolymers are comprised of monomers that individually form nonresponsive homopolymers, that is, only when copolymerized do they display thermoresponsive behavior. In this study, we sought to develop a predictive relationship between polymer hydrophobicity and cloud point temperature (T(CP)). A series of statistical copolymers were synthesized based on hydrophilic N,N-dimethyl acrylamide (DMA) and hydrophobic alkyl acrylate monomers, and their hydrophobicity was compared using surface area-normalized octanol/water partition coefficients (Log P(oct)/SA). Interestingly, a correlation between the Log P(oct)/SA of the copolymers and their T(CP)s was observed for the P(DMA-co-RA) copolymers, which allowed T(CP) prediction of a demonstrative copolymer P(DMA-co-MMA). These results highlight the strong potential of this computational tool to improve the rational design of copolymers with desired temperature responses prior to synthesis

Endocannabinoids modulate apoptosis in endometriosis and adenomyosis

Adenomyosis that is a form of endometriosis is the growth of ectopic endometrial tissue within the muscular wall of the uterus (myometrium), which may cause dysmenorrhea and infertility. Endocannabinoid mediated apoptotic mechanisms of endometriosis and adenomyosis are not known. We hypothesized that the down regulation of endocannabinoid receptors and/or alteration in their regulatory enzymes may have a direct role in the pathogenesis of endometriosis and adenomyosis through apoptosis. Endocannabinoid receptors CB1 and CB2, their synthesizing and catabolizing enzymes (FAAH, NAPE-PLD, DAGL, MAGL) and the apoptotic indexes were immunohistochemically assessed in endometriotic and adenomyotic tissues. Findings were compared to normal endometrium and myometrium. Endometrial adenocarcinoma (Ishikawa) and ovarian endometriosis cyst wall stromal (CRL-7566) cell lines were furthermore cultured with or without cannabinoid receptor agonists. The IC50 value for CB1 and CB2 receptor agonists was quantified. Cannabinoid agonists on cell death were investigated by Annexin-V/Propidium iodide labeling with flow cytometry. CB1 and CB2 receptor levels decreased in endometriotic and adenomyotic tissues compared to the control group (p = 0,001 and p = 0,001). FAAH, NAPE-PLD, MAGL and DAGL enzyme levels decreased in endometriotic and adenomyotic tissues compared to control (p = 0,001, p = 0,001, p = 0,001 and p = 0,002 respectively). Apoptotic cell indexes both in endometriotic and adenomyotic tissues also decreased significantly, compared to the control group (p = 0,001 and p = 0,001). CB1 and CB2 receptor agonist mediated dose dependent fast anti-proliferative and pro-apoptotic effects were detected in Ishikawa and ovarian endometriosis cyst wall stromal cell lines (CRI, 7566). Endocannabinoids are suggested to increase apoptosis mechanisms in endometriosis and adenomyosis. CB1 and CB2 antagonists can be considered as potential medical therapeutic agents for endometriosis and adenomyosis