Succinate Groups Research Articles

Electroacupuncture versus solifenacin succinate for female overactive bladder: study protocol for a multicentre, randomised, controlled, double-dummy, non-inferiority trial

IntroductionOveractive bladder (OAB) affects approximately 500 million people worldwide, with a higher prevalence in women than in men, significantly impacting the quality of life of female patients. Treatment options for...

Prevotella and succinate treatments altered gut microbiota, increased laying performance, and suppressed hepatic lipid accumulation in laying hens

BackgroundThis work aimed to investigate the potential benefits of administering Prevotella and its primary metabolite succinate on performance, hepatic lipid accumulation and gut microbiota in laying hens.ResultsOne hundred and fifty 58-week-old Hyline Brown laying hens, with laying rate below 80% and plasma triglyceride (TG) exceeding 5 mmol/L, were used in this study. The hens were randomly allocated into 5 groups and subjected to one of the following treatments: fed with a basal diet (negative control, NC), oral gavage of 3 mL/hen saline every other day (positive control, PC), gavage of 3 mL/hen Prevotella melaninogenica (107 CFU/mL, PM) or 3 mL/hen Prevotella copri (107 CFU/mL, P. copri) every other day, and basal diet supplemented with 0.25% sodium succinate (Succinate). The results showed that PM and P. copri treatments significantly improved laying rate compared to the PC (P < 0.05). The amount of lipid droplet was notably decreased by PM, P. copri, and Succinate treatments at week 4 and decreased by P. copri at week 8 (P < 0.05). Correspondingly, the plasma TG level in Succinate group was lower than that of PC (P < 0.05). Hepatic TG content, however, was not significantly influenced at week 4 and 8 (P > 0.05). PM treatment increased (P < 0.05) the mRNA levels of genes PGC-1β and APB-5B at week 4, and ACC and CPT-1 at week 8. The results indicated enhanced antioxidant activities at week 8, as evidenced by reduced hepatic malondialdehyde (MDA) level and improved antioxidant enzymes activities in PM and Succinate groups (P < 0.05). Supplementing with Prevotella or succinate can alter the cecal microbiota. Specifically, the abundance of Prevotella in the Succinate group was significantly higher than that in the other 4 groups at the family and genus levels (P < 0.05).ConclusionsOral intake of Prevotella and dietary supplementation of succinate can ameliorate lipid metabolism of laying hens. The beneficial effect of Prevotella is consistent across different species. The finding highlights that succinate, the primary metabolite of Prevotella, represents a more feasible feed additive for alleviating fatty liver in laying hens.

Synergistic chemoradiotherapy of cervical cancer cells using a pH- and radiation-sensitive doxorubicin-loaded β-cyclodextrin-based nanocomposite hydrogel containing MnO2 nanoparticles

It is an undoubted fact that remarkable clinical outcomes have demonstrated by synergistic chemoradiotherapy (CRT) approach, in comparison to solitary radiation therapy (RT) or chemotherapy (CT). Therefore, a novel pH- and radiation-sensitive nanocomposite hydrogel, β-cyclodextrin-graft-poly(succinic ethyl methacrylate)/MnO2 nanoparticles (β-CD-g-PSEMA/MnO2 NPs), was designed and developed through grafting 2-hydroxyethyl methacrylate (HEMA) onto functionalized β-CD through atom transfer radical polymerization (ATRP) followed by crosslinking β-CD-g-PHEMA-Br and bromine end-capped MnO2 NPs with Na2Se moiety to incorporate radiation-sensitive bonds into the hydrogel. The hydroxyl groups of PHEMA segments were converted to monomethyl succinate groups to induce pH sensitivity. Subsequently, the system was physically loaded with doxorubicin (Dox). In vitro drug release study revealed pH-dependent drug release behavior and the highest drug release value was obtained as 64.7% at pH 5. Oxygen generation from the developed drug delivery system (DDS) was confirmed, which the DDS could improve the efficiency of radiation therapy by oxygen generating in the cancer hypoxia environment. Intracellular uptake of the DDS was confirmed via FITC dye conjugation strategy. In contrast to free Dox, the developed DDS exhibited higher anticancer activity after 48 hours as validated by MTT and DAPI staining methods by synergistic CRT approach in moderate radiation dose.

Effect of Temperatures on Modification of Alginate Hydrophobicity using Dodecenyl Succinic Anhydride

Alginate is a highly hydrophilic polysaccharide as it contains several hydroxyl groups in the main backbone chain. Some applications for example as surfactants, however, require alginate to have higher hydrophobic properties. Hence, attempts are conducted to improve its hydrophobicity. Dodecenyl succinic anhydride (DSA) has a long hydrophobic chain that could substitute the hydroxyl groups of alginate and improve its hydrophobic properties. This study aimed to produce modified alginates with higher hydrophobicity using DSA as a modifier. The alginate modification was conducted at 30-70oC. The result showed that the degree of substitution (DS) increased in short time and low temperature of reaction. The highest DS value (0.1515) was obtained at 30oC for 30 min which gave the highest viscosity (14.74 cps) and the lowest surface tension (94.08 mN/m). The viscosity and surface tension values for the native alginate were 9.53 cps and 162,98 mN/m, respectively. Meanwhile, the viscosity and surface tension of the lowest DS (0.083) were 11.06 cps and 119.63 mN/m, respectively. The attachment of the dodecenyl succinic group was confirmed by the IR spectra as the presence of ester groups in the modified alginate.

Potential for infusion correction of COVID-19-associated endotheliopathy

To evaluate the relationship between the systemic inflammatory response and the severity of COVID-19-associated endotheliopathy and the effect of succinate-containing crystalloid solution (sodium meglumine succinate) on it in patients with severe COVID-19. Clinical and laboratory parameters of 53 intensive care unit's patients with COVID-19 complicated by community-acquired bilateral multisegmental pneumonia were analyzed. Intensive therapy complex of 27 patients (study group) included daily infusion of 1.5% solution of sodium meglumine succinate (Reamberin) in the daily dose of 10 ml/kg for at least 11 days (or during the whole stay in the unit). A similar volume of Ringer's solution was present in the control group of 26 patients. The levels of endotheliocytosis, homocysteine, and systemic inflammatory response were determined at all stages of the study. The evaluation of endotheliopathy degree in the meglumine succinate group showed a significant reduction of initially elevated levels of endotheliemia and homocysteinemia at all study stages. The pattern of changes in the study group was highly correlated (r=0.90-0.96) with the dynamics of systemic inflammatory response parameters-fibrinogenemia, C-reactive protein and interleukin-6 levels. As normalization of the immune imbalance, we regarded the termination of lymphopenia in the Reamberin group. Early inclusion of Reamberin infusion into intensive therapy of severe COVID-19, in comparison with Ringer's solution, leads to significant and stable correction of the severity of systemic inflammatory response, which in turn is naturally reflected in the severity of endothelial dysfunction, multiple organ failure, and also leads to a decrease in 28-day mortality.

Preparation and Physico-Chemical Characterization of OSA-Modified Starches from Different Botanical Origins and Study on the Properties of Pickering Emulsions Stabilized by These Starches.

Native starch (NS) from different botanical origins (native rice/tapioca/oat starch, NRS/NTS/NOS) were hydrophobically modified by octenyl succinic anhydride (OSA), and the octenyl succinic (OS) groups were successfully introduced in the starch molecules which obtained OS-starch (OSRS, OSTS and OSOS) with different levels of modification (0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%) and degree of substitution (DS). The structural properties of the OS-starch, such as granule size, crystal, wettability and morphology were studied, and the OS-starch was used as particulate stabilizers to produce oil-in-water (O/W) Pickering emulsions. The emulsion index, droplet size distribution and microstructures of Pickering emulsions produced by different OS-starches were compared. OSA modification had almost no effect on the morphology or crystal structure types of three kinds of NS and OS-starch but markedly increased the contact angle and particle size distribution of OSRS, OSTS and OSOS. Esterification reaction of OSA and starch mainly occurred in amorphous regions of starch, and the OSA significantly improved the emulsifying capacity of OSRS, OSTS and OSOS granules and thus stabilized emulsions formed at higher levels (2.5% and 3.0%) of modification of OS-Starch exhibited better stability; the ability of OS-starch to stabilize Pickering emulsion was 3.0% OSRS > 3.0% OSOS > 3.0% OSTS, respectively. Observation and structural properties analysis of OS-starch granules and Pickering emulsion droplets showed that the number and thickness of the starch granules on the oil-water interface of the emulsion droplets increased with improvement of the OSA modification level, and an aggregation state was formed between the OS-starch granules, which was also enhanced with the OSA modification levels. These were all necessary for the Pickering emulsion stabilized by starch granules to remain in a steady state.

To rationalize the substitution priority of octenyl succinic group along amylopectin chain: An analysis from the change of lamellar structure

Under controlled supply of octenyl succinic anhydride (OSA), the priority of OSA substitution along amylopectin chain was revealed to follow backbone branch-branching point-chain pattern in our previous study, but whether or how this priority pattern was related to the distribution of amylopectin chains within undispersed starch granule was unclear. To reveal the reason for this substitution priority of OSA, changes in the lamellar structure associated with the branching point and chain structure of amylopectin, were studied. Firstly, X-ray diffraction (XRD) test suggested that initial branching-point substitutions at low substitution degree (DS, ≤0.7%) could decrease the crystallinity of starch. A 0.08 nm increase in the thickness of intermediate region and a 9.5% reduction in the lamellar compactness (Dm) were revealed by small angle X-ray scattering, indicating that initial structural changes were resulted from the substitution of backbone branch closely connected to crystal region. When DS reached 1.5%, the loosened lamellar structure triggered branch-chain substitutions, leading to a 6% decrease in β-limit value, despite largely available branching points at this point. Then, the chain substitution resulted in increased thickness of crystalline lamellae dc and further reduced Dm, which in turn promoted more chain substitutions at high DS. Changes in the lamellar structure, crystallinity, granular morphology, particle size and the substituent distribution of starch well rationalized the ordered substitution of OSA at molecular level.

In Vitro Bioaccessibility of Bioactive Compounds of Freeze-Dried Orange Juice Co-Product Formulated with Gum Arabic and Modified Starch

The large amount of waste generated by the orange juice industry has sparked the interest of many researchers in incorporating recycling systems and following a much more sustainable circular economy model. This work proposes the valorization of the co-product generated in the orange juice extraction industry after freeze-drying for its subsequent reuse as a natural ingredient in the food industry. In addition, the possible protective effect of gum Arabic and corn starch esterified with octenyl succinic groups, in proportions optimised in previous studies 0.25 and 0.45 g/g orange co-product dry solutes, on the main bioactive compounds of orange peel during the freeze-drying process has been studied. The samples were characterised for their content of vitamin C (ascorbic and dehydroascorbic acids), flavonoids (hesperidin and narirutin), total phenols and total carotenoids, as well as their antioxidant capacity (DPPH and FRAP assays). In addition, samples were digested, mimicking the human enzymatic oral gastro-intestinal digestion process, and the bioaccessibility of the bioactive compounds was evaluated. It was observed that the addition of both biopolymers improved the stability of the hydrophilic compounds during freeze-drying. This conservative effect was more remarkable for higher biopolymer concentrations. However, no protective effect on carotenoid compounds was observed. This trend was reflected in the antioxidant activity of the different samples. In addition, the incorporation of biopolymers improved the bioaccessibility of the bioactive compounds studied. In conclusion, the results supported the feasibility of the freeze-dried orange juice co-product as a natural, sustainable source of health-promoting compounds.

Amiodarone vs. metoprolol succinate in HFrEF complicated with persistent atrial fibrillation with rapid ventricular response: A prospective observational study.

β-blockers have been recommended for patients with heart failure (HF) and atrial fibrillation (AF), but studies have shown that β-blockers do not reduce all-cause mortality or cardiovascular mortality in patients with HF and AF. To investigate the difference in efficacy between oral amiodarone and metoprolol succinate for patients with HF with reduced ejection fraction (HFrEF) and persistent atrial fibrillation (pAF) with rapid ventricular response (RVR). Patients with HFrEF complicated with pAF with RVR treated in the People's Hospital of Chongqing Hechuan between March 2018 and March 2019 were enrolled in this prospective observational study. The primary outcomes were cardiovascular mortality and the first hospitalization for HF rate. The secondary outcomes were type B pro-brain natriuretic peptide (NT-proBNP) before/after treatment, left ventricular ejection fraction (LVEF) before/after treatment, average heart rate (AhR), and the rate of sinus rhythm after 1 year of follow-up. A total of 242 patients with HFrEF complicated with pAF with RVR were enrolled and divided into amiodarone + perindopril + spironolactone+ routine drug (amiodarone group, n = 121) and metoprolol succinate + perindopril + spironolactone +routine drug (metoprolol succinate group, n = 121) according to their treatment strategy. Cardiovascular mortality (4.9 vs. 12.4%, HR: 2.500, 95%CI: 1.002-6.237, P = 0.040) and first hospitalization for HF (52.9 vs. 67.8%, HR: 1.281, 95%CI: 1.033-1.589, P = 0.024) were significantly lower in the amiodarone group than in the metoprolol group. The mean ventricular rate in the amiodarone group was significantly lower than in the metoprolol group (64.5 ± 3.2 vs. 72.4 ± 4.2, P < 0.001). After 1 year of follow-up, the sinus rhythm rate was significantly higher in the amiodarone group than in the metoprolol group (38.8 vs. 7.4%, HR: 0.191, 95%CI: 0.098-0.374, P < 0.001). The difference in proBNP (3,914.88 vs. 2,558.07, P < 0.001) and LVEF (-6.89 vs. -0.98, P < 0.001) before and after treatment was significantly higher in the amiodarone group than in the metoprolol group. In conclusion, in this prospective observational study, the amiodarone group had lower risk of cardiovascular death and the first hospitalization for HF than metoprolol in HFrEF and persistent atrial fibrillation (pAF) with RVR. The mechanism may be related to improved cardiac function, rhythm control and ventricular rate control. ChiCTR2200057816; Registered 7 March 2022-Retrospectively registered: http://www.medresman.org.cn/pub/cn/proj/projectshshow.aspx?proj=4222.

Succinate Induces Liver Damage and Hepatic Fibrosis in a Mouse Model

Hepatic stellate cells (HSCs) play a key role in liver fibrosis. Succinate and succinate receptor (GPR91) signaling pathway are involved in the activation, proliferation, and migration of HSCs. We investigated whether succinate may induce hepatic fibrosis. The mice were randomly divided into 2 groups —the control group (chow diet-fed mice, n = 26) and sodium succinate group (2% sodium succinate + chow diet, n = 38). Each diet was provided for 16 weeks. Mice administered an oral diet of 2% sodium succinate for sixteen weeks lost body weight and had increased serum alanine transaminase and hepatic triglyceride contents compared to those in the control mice. Moreover, mice fed with sodium succinate showed increased expression of the alpha smooth muscle actin protein and gene in the liver at 8 weeks of feeding and increased fibrosis in their histology at 16 weeks of feeding. However, the expression of the GPR91 protein and mRNA increased at 4 weeks of feeding, but decreased at 8 and 16 weeks of feeding. These results suggest that an oral succinate diet could induce liver damage and liver fibrosis in mice and that GPR91 signaling might be an early marker or sensor of hepatic fibrosis development.

Structure and Menthone Encapsulation of Corn Starch Modified by Octenyl Succinic Anhydride and Enzymatic Treatment

In order to improve the ability of starch to absorb menthone, corn starch was modified by enzymatic treatment (amyloglucosidase and α-amylase) combined with octenyl succinic anhydride (OSA) esterification. The oil absorption rate of starch modified by enzymatic treatment followed by OSA (P-OSA) reached 101.33%, whereas that of samples with reverse action sequences (OSA-P) was only 59.67%. The degree of substitution of OSA-P was also generally lower than that of P-OSA. At high OSA addition, OSA-P had a smaller specific surface area with fewer pores because octenyl succinic (OS) groups impeded the enzymatic treatment. Compared with OSA-P, the lamellar structure of P-OSA is sparser and less ordered. Owing to its pores, P-OSA was beneficial for the reaction to occur inside the granules, which was observed by Raman spectroscopy and laser confocal microscopy. At high OSA addition, the loading of P-OSA to menthone could reach 64.34 mg/g.

Comparison of alpha-blockers and antimuscarinic for the treatment of double-J stent-related lower urinary tract symptoms.

Background: Double-J stent is well known for relieving urinary tract obstruction, but still, some patients might develop double-J stent-related urinary tract infection (UTI), lower urinary tract symptoms (LUTS), lower abdominal pain, and hematuria. This study aims to compare alpha-blockers and antimuscarinics for the treatment of double-j stent-related lower urinary tract symptoms.&#x0D; Methodology: Patients planned for double-J stent insertion undergoing the urological procedure for ureteric stones were recruited and randomly allocated into two groups. One group was labeled as the tamsulosin (T), and the other was labeled as the solifenacin succinate (S) group. Group" T" patients were prescribed tamsulosin 0.4 mg once at bedtime and solifenacin succinate 10mg once daily to group "S" for 2 weeks. Improvement in symptoms was checked by means of international prostate symptom score (IPSS)/ quality of life (QoL) score charts for LUTS in the out-patient clinic at baseline and at follow-up. &#x0D; Results: When comparing the absolute changes in IPSS/QoL for LUTS scores, both groups showed significant improvement in double-J stent-related lower urinary symptoms, body pain, generalized body weakness, and sexual function, which affect their quality of life (QoL). The mean index score of all domains in both groups was significantly less (p&lt;0.001). Tamsulosin and solifenacin succinate (S) group was found equally efficacious on urinary symptoms (26.01 ± 5.65 (pre); 5.74 ± 0.99 (post) vs. 26.61 ± 5.7 (pre); 26.01 ± 0.97 (post), (p≤0.001). Similarly, the score of QoI was also found equally efficacious in both groups in pre and post-insertion on two weeks (4.96 ± 0.7 (pre); 81.58 ± 0.64 (post) vs. 4.99 ± 0.81 (pre); 1.45 ± 0.5 (post) (p&lt;0.001).&#x0D; Conclusion: On the basis of results, it is said that a combination of alpha-blockers and antimuscarinic agents has shown significant improvement to reduce double-J stent-related lower urinary symptoms, pain, and quality of life than a single drug alone.

Dietary succinate supplementation to maternal mice improves fetal brown adipose tissue development and thermogenesis of female offspring

Succinic acid widely exists in foods and is used as a food additive. Succinate not only serves as an energy substrate, but also induces protein succinylation. Histone succinylation activates gene transcription. The brown adipose tissue (BAT) is critical for prevention of obesity and metabolic dysfunction, and the fetal stage is pivotal for BAT development. Up to now, the role of maternal succinate supplementation on fetal BAT development and offspring BAT function remains unexamined. To test, female C57BL/6J mice (2-month-old) were separated into 2 groups, received with or without 0.5% succinic acid in drinking water during gestation and lactation. After weaning, female offspring were challenged with high fat diet (HFD) for 12 weeks. Newborn, female weanling, and HFD female offspring mice were analyzed. For neonatal and weaning mice, the BAT weight relative to the whole body weight was significantly increased in the succinate group. The expression of PGC-1α, a key transcription co-activator promoting mitochondrial biogenesis, was elevated in BAT of female neonatal and offspring born to succinate-fed dams. Consistently, maternal succinate supplementation enhanced thermogenesis and the expression of thermogenic genes in offspring BAT. Additionally, maternal succinate supplementation protected female offspring against HFD-induced obesity. Furthermore, in C3H10T1/2 cells, succinate supplementation promoted PGC-1α expression and brown adipogenesis. Mechanistically, succinate supplementation increased permissive histone succinylation and H3K4me3 modification in the Ppargc1a promoter, which correlated with the higher expression of Ppargc1a. In conclusion, maternal succinate supplementation during pregnancy and lactation enhanced fetal BAT development and offspring BAT thermogenesis, which prevented HFD-induced obesity and metabolism dysfunction in offspring.

Succinate Injection Rescues Vasculature and Improves Functional Recovery Following Acute Peripheral Ischemia in Rodents: A Multimodal Imaging Study.

Succinate influences angiogenesis and neovascularization via a hormonelike effect on G-protein-coupled receptor 91 (GPR91). This effect has been demonstrated in the pathophysiology of diabetic retinopathy and rheumatoid arthritis. To evaluate whether succinate can play a role in acute peripheral ischemia, a preclinical study was conducted with ischemic mice treated with succinate or PBS and evaluated by imaging. Acute ischemia was followed by an increased in GPR91 expression in the ischemic muscle. As assessed with LASER-Doppler, succinate treatment resulted in an earlier and more intense reperfusion of the ischemic hindlimb compared to the control group (* p = 0.0189). A microPET study using a radiolabeled integrin ligand ([68Ga]Ga-RGD2) showed an earlier angiogenic activation in the succinate arm compared to control mice (* p = 0.020) with a prolonged effect. Additionally, clinical recovery following ischemia was better in the succinate group. In conclusion, succinate injection promotes earlier angiogenesis after ischemia, resulting in a more effective revascularization and subsequently a better functional recovery.

Impact of Maltodextrin, Gum Arabic, Different Fibres and Starches on the Properties of Freeze-Dried Orange Puree Powder

Fruits are essential components of a healthy diet contributing to the prevention of different diseases. Nevertheless, their consumption is limited among the population for reasons of convenience, among others. High-quality products are obtained by freeze-drying; however, dehydrated fruit presents a physical stability problem associated with the glass transition of its amorphous matrix. A common technique to prevent the rubbery state is the incorporation of biopolymers that contribute to increasing the glass transition temperature or that may exert a steric role. Nevertheless, the chemical composition and physical properties of these biopolymers may affect the quality of the dehydrated product which could compromise its use for specific applications. This work studies the impact of gum Arabic, bamboo fibre, maltodextrin, pea fibre, starch substituted with octenyl succinic groups and native corn starch added to an orange puree, on powder flowability and rehydration behaviour of the freeze-dried fruit powder. As regards the flowability, according to the angle of repose values (37–42°), all powder formulations were considered in the range of ‘acceptable’ powders. However, both samples containing maltodextrin showed significantly the lowest angle of repose value (37–38°), and therefore a better flowability. Samples containing gum Arabic, bamboo fibre and maltodextrin showed the lower wetting time (175–570 s), which is desired for rehydration, compared to those formulated with OSA (914–1887 s). Moreover, sample with gum Arabic showed the lowest viscosity after rehydration (0.199 Pas), desired to be consumed as a juice. According to the obtained results, if to get an orange puree powder with a good flowability is desired, the use of maltodextrin may be recommended. However, if rehydration is preferred, the use of gum Arabic is more recommended.

Free radical mechanism for reactive processing of polymers in the presence of organoclay/peroxide nanoreactors: Grafting maleic anhydride onto polypropylene

PP-graft-MA is a common PP compatibilizer, produced via reactive extrusion using peroxides as initiator, which causes severe molar mass reduction. To control PP degradation and increase maleic anhydride grafting, Shi and coworkers (2006), proposed the use of nanoreactors. In this paper we propose a complete new reactive mechanism involving nanoreactors during PP-graft-MA reactive processing. The samples were prepared via melt mixing using nanoreactors with different organoclay: peroxide ratios (oMMT:DCP). Organic MMT showed to absorb not more than 16 wt% of DCP, i.e., diffusional controlled release of alkoxy radical will not be observed at o-MMT:DCP ratios < 5:1. The presence of o-MMT tend to increase MA homopolymerization, which consumes the initiator, interfering with the grafting of succinic groups onto the PP backbone, due to increased hindrance of oligo (MA) formed, thereby reducing degradation of the PP chain. Thus, the use of nanoreactors promotes MA homopolymerization rather than grafting as previously proposed in the literature.

Facile preparation of tertiary amine grafted poly (α,β-L-aspartic acid) with zwitterionic property to limit nonspecific protein adsorption

A series of poly (amino acid) with zwitterionic character was prepared for surface coating to avoid protein adsorption, by modifying the poly (aspartic acid) side chain with tertiary amine groups. An interesting and facile procedure is described with starts with polysuccinic acid which is followed by ring-opening with amino functions and finally hydrolysis of the remaining succinic acid groups achieving the polyaspartic acid structure as backbone. The degree of cationic tertiary amino group was easily varied by the degree of ring-opening with amines. The materials show isoelectric point between pH 4 and 9, have a typical zwitterionic character, and can be used to coat negatively as well as positively charged surfaces, depending on composition. The protein adsorption behavior is thus pH dependent and was studied with various proteins mainly available in blood. The adsorption test proved that a significant reduction of protein adsorption could be found for fibrinogen and albumin, and this protein-repellent behavior is strongly dependent on the amount of the absorbed polymer (adsorbed at pH = 7.4). This is a nice additional contribution to polymers with zwitterionic character used as coating reducing nonspecific protein adsorption.

The effect of thermal and irradiation treatments on structural and physicochemical properties of octenyl succinate maize starches.

The aim of this paper was to evaluate the effect of thermal treatment and UV irradiation on structural and physicochemical properties of octenyl succinate (OS) maize starches differing in content of OS groups (0.76%-2.38%). X-ray diffraction (XRD), gel permeation chromatography (GPC), and electron paramagnetic resonance (EPR) spectroscopy were used to estimate structural characteristics of octenyl succinate starches and their physically treated counterparts. Starch functional properties were also determined. XRD spectra and hydrodynamic volume distribution revealed that growth of octenyl succinate groups' content resulted in stabilization of starch structure, which was confirmed by processes of radical formation, stimulated by thermal and UV treatments. It was found, on the basis of measurements of water binding capacity, water solubility and intrinsic viscosity, that OSA addition changed physicochemical properties of starch and influenced the course of physical modifications. It was established that temperature affected starch properties to a greater extent than UV.

Effect of dual chemical modification on the properties of biodegradable films from achira starch

AbstractThe objective of this study was to evaluate the effect of a dual modification (acid hydrolysis and succination) on the structural, mechanical, thermomechanical, and permeability properties of films from achira starch. Micrographs of films revealed a smooth surface and some remnants of starch granules, indicating a partial gelatinization. Tensile strength and percentage of elongation increased in films from double modified starch (10.50 MPa and 42.83%, respectively). The OH groups formed in the amylose and amylopectin chains during the hydrolysis and the alkoxide groups (RO−) generated during the succination resulted in high values of water vapor permeability (3.215 × 10−10 g/s m Pa). The glass transition temperature (Tg) of films from hydrolyzed–succinated starch was decreased due to the reduction of the molecular weight of the polymeric chains and the presence of succinate groups that reduced the molecular interactions of the polymeric chains, increasing the mobility and therefore decreasing the softening temperature.

Effect of Drug-Polymer Interactions through Hypromellose Acetate Succinate Substituents on the Physical Stability on Solid Dispersions Studied by Fourier-Transform Infrared and Solid-State Nuclear Magnetic Resonance.

The present study evaluated the specific intermolecular interactions between carbamazepine (CBZ) and substituents of hypromellose acetate succinate (HPMC-AS), as well as the mechanism of inhibition of recrystallization of solid dispersions (SDs) using Fourier-transform infrared (FTIR) and solid-state nuclear magnetic resonance (NMR) spectroscopy. CBZ and HPMC derivatives, including HPMC, hypromellose acetate (HPMC-A), and hypromellose succinate (HPMC-S), were spray-dried to prepare CBZ/polymer spray-dried samples (SPDs). CBZ/HPMC SPD and CBZ/HPMC-A SPD recrystallized within 10 days at 60 °C and 0% relative humidity, whereas CBZ/HPMC-S SPD maintained its amorphous state for a longer period. FTIR and solid-state NMR measurements using 13C cross polarization (CP), 1H single-pulse, and 1H-15N CP-based heteronuclear single quantum correlation filter experiment with very fast magic angle spinning (MAS) at 70 kHz identified molecular interactions in CBZ/polymer SPDs. Although the HPMC backbone and substituents did not interact notably with CBZ and disrupt CBZ-CBZ intermolecular interactions (formed in the amorphous CBZ), acetate and succinate substituents on HPMC-A and HPMC-S disrupted CBZ-CBZ intermolecular interactions through formation of CBZ/polymer interactions. The acetate substituent formed a hydrogen bond with the NH2 group of CBZ, whereas the succinate substituent formed molecular interactions with both the C═O and NH2 groups of CBZ. Formation of relatively strong molecular interactions between CBZ and the succinate substituent followed by disruption of CBZ-CBZ intermolecular interactions effectively stabilized the amorphous state of CBZ in CBZ/HPMC-S SPD. The correlation between CBZ-polymer interactions and ability of polymers to effectively inhibit CBZ recrystallization is reflected in various commercial HPMC-AS. For example, HPMC-AS LF grade, containing higher amounts of the succinate group, was found to effectively inhibit the recrystallization of CBZ through strong molecular interactions as compared with the HPMC-AS HF grade. The present study demonstrated that a detailed investigation of molecular interactions between the drug and the polymer using FTIR and solid-state NMR spectroscopy could contribute to a suitable selection of the SD carrier.