scholarly journals Biostable Shape Memory Polymer Foams for Smart Biomaterial Applications

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4084
Author(s):  
Anand Utpal Vakil ◽  
Natalie Marie Petryk ◽  
Ellen Shepherd ◽  
Mary Beth B. Monroe

Polyurethane foams provide a wide range of applications as a biomaterial system due to the ability to tune their physical, chemical, and biological properties to meet the requirements of the intended applications. Another key parameter that determines the usability of this biomaterial is its degradability under body conditions. Several current approaches focus on slowing the degradation rate for applications that require the implant to be present for a longer time frame (over 100 days). Here, biostable shape memory polymer (SMP) foams were synthesized with added ether-containing monomers to tune the degradation rates. The physical, thermal and shape memory properties of these foams were characterized along with their cytocompatibility and blood interactions. Degradation profiles were assessed in vitro in oxidative (3% H2O2; real-time) and hydrolytic media (0.1 M NaOH; accelerated) at 37 °C. The resulting foams had tunable degradation rates, with up 15% mass remaining after 108 days, and controlled erosion profiles. These easy-to-use, shape-filling SMP foams have the potential for various biomaterial applications where longer-term stability without the need for implant removal is desired.

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2290
Author(s):  
Sayyeda Marziya Hasan ◽  
Grace K. Fletcher ◽  
Mary Beth Browning Monroe ◽  
Mark A. Wierzbicki ◽  
Landon D. Nash ◽  
...  

Shape memory polymer foams have been used in a wide range of medical applications, including, but not limited to, vessel occlusion and aneurysm treatment. This unique polymer system has been proven to shape-fill a void, which makes it useful for occlusion applications. While the shape memory polymer foam has superior performance and healing outcomes compared to its leading competitors, some device applications may benefit from longer material degradation times, or degradation-resistant formulations with increased fibrous encapsulation. In this study, biostable shape memory polymer foams were synthesized, and their physical and chemical properties were characterized as an initial evaluation of feasibility for vascular occlusion applications. After characterizing their shape memory behavior in an aqueous environment, degradation of this polymer system was studied in vitro using accelerated oxidative and hydrolytic solutions. Results indicated that the foams did not lose mass under oxidative or hydrolytic conditions, and they maintained high shape recovery in aqueous in vitro models. These degradation-resistant systems have potential for use in vascular occlusion and other wound healing applications that benefit from permanent, space-filling shape memory behavior.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3579
Author(s):  
Svetlana A. Popova ◽  
Evgenia V. Pavlova ◽  
Oksana G. Shevchenko ◽  
Irina Yu. Chukicheva ◽  
Aleksandr V. Kutchin

The pyrazoline ring is defined as a “privileged structure” in medicinal chemistry. A variety of pharmacological properties of pyrazolines is associated with the nature and position of various substituents, which is especially evident in diarylpyrazolines. Compounds with a chalcone fragment show a wide range of biological properties as well as high reactivity which is primarily due to the presence of an α, β-unsaturated carbonyl system. At the same time, bicyclic monoterpenoids deserve special attention as a source of a key structural block or as one of the pharmacophore components of biologically active molecules. A series of new diarylpyrazoline derivatives based on isobornylchalcones with different substitutes (MeO, Hal, NO2, N(Me)2) was synthesized. Antioxidant properties of the obtained compounds were comparatively evaluated using in vitro model Fe2+/ascorbate-initiated lipid peroxidation in the substrate containing brain lipids of laboratory mice. It was demonstrated that the combination of the electron-donating group in the para-position of ring B and OH-group in the ring A in the structure of chalcone fragment provides significant antioxidant activity of synthesized diarylpyrazoline derivatives.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4246 ◽  
Author(s):  
Yujie Chen ◽  
Chi Chen ◽  
Hafeez Ur Rehman ◽  
Xu Zheng ◽  
Hua Li ◽  
...  

Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. Recently, significant achievements have been made in fabrication, modelling, and manipulation of SMP-based artificial muscles. This paper presents a review of the recent progress in shape-memory polymer-based artificial muscles. Here we focus on the mechanisms of SMPs, applications of SMPs as artificial muscles, and the challenges they face concerning actuation. While shape-memory behavior has been demonstrated in several stimulated environments, our focus is on thermal-, photo-, and electrical-actuated SMP artificial muscles.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 596 ◽  
Author(s):  
María del Carmen Villegas-Aguilar ◽  
Álvaro Fernández-Ochoa ◽  
María de la Luz Cádiz-Gurrea ◽  
Sandra Pimentel-Moral ◽  
Jesús Lozano-Sánchez ◽  
...  

Dietary phenolic compounds are considered as bioactive compounds that have effects in different chronic disorders related to oxidative stress, inflammation process, or aging. These compounds, coming from a wide range of natural sources, have shown a pleiotropic behavior on key proteins that act as regulators. In this sense, this review aims to compile information on the effect exerted by the phenolic compounds and their metabolites on the main metabolic pathways involved in energy metabolism, inflammatory response, aging and their relationship with the biological properties reported in high prevalence chronic diseases. Numerous in vitro and in vivo studies have demonstrated their pleiotropic molecular mechanisms of action and these findings raise the possibility that phenolic compounds have a wide variety of roles in different targets.


2007 ◽  
Vol 6 (1) ◽  
Author(s):  
Géraldine M Baer ◽  
Ward Small ◽  
Thomas S Wilson ◽  
William J Benett ◽  
Dennis L Matthews ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6550
Author(s):  
Vladislav I. Deigin ◽  
Julia E. Vinogradova ◽  
Dmitry L Vinogradov ◽  
Marina S. Krasilshchikova ◽  
Vadim T. Ivanov

The paper summarizes the available information concerning the biological properties and biomedical applications of Thymodepressin. This synthetic peptide drug displays pronounced immunoinhibitory activity across a wide range of conditions in vitro and in vivo. The history of its unforeseen discovery is briefly reviewed, and the current as well as potential expansion areas of medicinal practice are outlined. Additional experimental evidence is obtained, demonstrating several potential advantages of Thymodepressin over another actively used immunosuppressor drug, cyclosporin A.


2017 ◽  
Vol 71 (0) ◽  
pp. 0-0
Author(s):  
Paulina Dębek ◽  
Agnieszka Feliczak-Guzik ◽  
Izabela Nowak

The general tendency towards the miniaturization of technological systems and materials has prompted intensive development of nanotechnology. It is a quickly developing area of science devoted to the production and application of nanomaterial structures defined as those whose one size does not exceed 100 nm. Nanostructures have been found to show new physical, chemical and biological properties often better than the corresponding materials made of particles of micrometric or macrometric sizes, so they have become of great interest in many areas of industry as well as other areas [22], such as medicine and cosmetology. According to literature and Scopus database, Fig. 1, the most popular nanostructures used in medicine and cosmetology, besides silver and gold nanoparticles, are those of other transition metals such as platinum, palladium or ruthenium. This paper is concerned with the wide range of present and potential applications of nanomaterials in medicine and cosmetology.


Author(s):  
Nieves Baenas ◽  
Jenny Ruales ◽  
Diego A. Moreno ◽  
Daniel Alejandro Barrio ◽  
Carla M. Stinco ◽  
...  

Andean blueberries are wild berries grown and consumed in Ecuador which contain high values of bioactive compounds, mainly anthocyanins, with powerful antioxidant activity. The aim of this study was to evaluate the profile and contents of (poly)phenols and carotenoids in Andean blueberry by HPLC-DAD-MSn and determine a wide range of its biological activities. The antioxidant capacity of this fruit was evaluated in vitro by three different methods and in vivo using the zebrafish animal model, also the toxicity effect was determined by the zebrafish embryogenesis test. Besides, the antimicrobial activity and the capacity of Andean blueberry to produce hemagglutination in blood cells were evaluated. Finally, the bioaccessibility of (poly)phenols and related antioxidant capacity were determined in the different phases of an in vitro digestion. The global results indicated no toxicity of Andean blueberry, weakly bacteriostatic activity, and high contents of anthocyanins and antioxidant capacity, which were partially bioaccesible in vitro (~ 50 % at the final intestinal step), contributing to the knowledge of its health benefits for consumers and its potential use in the food and pharmaceutical industry as functional ingredient.


2017 ◽  
Vol 15 (1) ◽  
pp. 82-91
Author(s):  
Daniela Batista ◽  
Pedro L. Falé ◽  
Maria L. Serralheiro ◽  
Maria-Eduarda Araújo ◽  
Catarina Dias ◽  
...  

AbstractPlants belonging to the genus Salvia (Lamiaceae) are known to have a wide range of biological properties. In this work, extracts obtained from the aerial parts of Salvia sclareoides Brot. were evaluated to investigate their chemical composition, toxicity, bioactivity, and stability under in vitro gastrointestinal conditions. The composition of the supercritical fluid extract was determined by GC and GC-MS, while the identification of the infusion constituents was performed by HPLC-DAD and LC-MS. The in vitro cytotoxicity of both extracts (0-2 mg/mL) was evaluated in Caco-2 cell lines by the MTT assay. The anti-inflammatory and anticholinesterase activities were determined through the inhibition of cyclooxygenase-1 and acetylcholinesterase enzymes, while β-carotene/linoleic acid bleaching test and the DPPH assays were used to evaluate the antioxidant activity. The infusion inhibited cyclooxygenase-1 (IC50 = 271.0 μg/mL), and acetylcholinesterase (IC50 = 487.7 μg/ mL) enzymes, also demonstrated significant antioxidant properties, as evaluated by the DPPH (IC50 = 10.4 μg/mL) and β-carotene/linoleic acid (IC50 = 30.0 μg/mL) assays. No remarkable alterations in the composition or in the bioactivities of the infusion were observed after in vitro digestion, which supports the potential of S. sclareoides as a source of bioactive ingredients with neuroprotective, anti-inflammatory and antioxidant properties.


2019 ◽  
Vol 65 (2) ◽  
pp. 99-102 ◽  
Author(s):  
Yu.V. Butina ◽  
T.V. Kudayarova ◽  
E.A. Danilova ◽  
M.K. Islyaikin

The work is devoted to predicting and studying biological properties of N-substituted analogs of 3,5-diamino-1,2,4-thiadiazole, which, in their turn, include in the composition of many drugs that exhibit a wide range of pharmacological actions. For searching of new alternative drugs with an antibacterial activity, but lacking resistance of microorganism strains to them, a computer screening of 2N-alkyl-substituted 5-amino-3-imino-1,2,4-thiadiazolines previously synthesized by us was carried out. The prediction of the spectrum of biological activity, as well as the determination of the probable toxicity of these compounds, was performed using the freely available computer programs PASS, Anti-Bac-Pred, and GUSAR. The study of the antibacterial activity in vitro against gram-positive (Staphylococcus aureus, Staphylococcus saprophyticus, Staphylococcus epidermidis) and gram-negative (Escherichia coli, Pseudomonas aeruginosae) bacterial strains was performed by the disco-diffusion method. Experimental data roughly correspond to the predictions.


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