pH responsive tragacanth gum and poly(methyl methacrylate-co-maleic anhydride)-g-poly(caprolactone) conetwork microgel for in vitro quercetin release

Polymer ◽  
2015 ◽  
Vol 59 ◽  
pp. 49-56 ◽  
Author(s):  
Khadijeh Hemmati ◽  
Arameh Masoumi ◽  
Mousa Ghaemy
1987 ◽  
Vol 52 (9) ◽  
pp. 2194-2203
Author(s):  
Miloslav Kučera ◽  
Dušan Kimmer ◽  
Karla Majerová ◽  
Josef Majer

In the reaction of dianions with poly(methyl methacrylate), only an insignificant amount of insoluble crosslinked product is obtained. If, however, the concentration of grafting dianions approaches that of ester groups, the amount of poly(methyl methacrylate) which may thus be crosslinked becomes quite significant. Dications, too, can bring about crosslinking of only an insignificant number of poly(methyl methacrylate) chains. Carboxylic groups in poly(acrylic acid) react with dianions and dications in an anhydrous medium similarly to ester groups. On the other hand, in the presence of a cocatalytic amount of water dications are more readily bound to carboxylic groups, forming a covalent bond. The relatively highest efficiency was observed in the bond formation between dication and the poly[styrene-alt-(maleic anhydride)], both in an anhydrous medium and in the presence of H2O.


2021 ◽  
Vol 22 (3) ◽  
pp. 1441
Author(s):  
Antonio Scarano ◽  
Tiziana Orsini ◽  
Fabio Di Carlo ◽  
Luca Valbonetti ◽  
Felice Lorusso

Background—the graphene-doping procedure represents a useful procedure to improve the mechanical, physical and biological response of several Polymethyl methacrylate (PMMA)-derived polymers and biomaterials for dental applications. The aim of this study was to evaluate osseointegration of Graphene doped Poly(methyl methacrylate) (GD-PMMA) compared with PMMA as potential materials for dental implant devices. Methods—eighteen adult New Zealand white male rabbits with a mean weight of approx. 3000 g were used in this research. A total of eighteen implants of 3.5 mm diameter and 11 mm length in GD-PMMA and eighteen implants in PMMA were used. The implants were placed into the articular femoral knee joint. The animals were sacrificed after 15, 30 and 60 days and the specimens were evaluated by µCT and histomorphometry. Results—microscopically, all 36 implants, 18 in PMMA and 18 in DG-PMMA were well-integrated into the bone. The implants were in contact with cortical bone along the upper threads, while the lower threads were in contact with either newly formed bone or with marrow spaces. The histomorphometry and µCT evaluation showed that the GP-PMMA and PMMA implants were well osseointegrated and the bone was in direct contact with large portions of the implant surfaces, including the space in the medullary canal. Conclusions—in conclusion, the results suggest that GD-PMMA titanium surfaces enhance osseointegration in rabbit femurs. This encourages further research to obtain GD-PMMA with a greater radiopacity. Also, further in vitro and vivo animal studies are necessary to evaluate a potential clinical usage for dental implant applications.


RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 43915-43926
Author(s):  
Eszter Hajba-Horváth ◽  
Emese Biró ◽  
Mirella Mirankó ◽  
Andrea Fodor-Kardos ◽  
László Trif ◽  
...  

Valsartan-loaded ethyl cellulose and poly(methyl methacrylate) nanoparticles were prepared and nano spray-dried. The active agent was structurally changed in the nanoparticles, which could be advantageous in the intestinal absorption.


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