Physically crosslinked polyvinyl alcohol and gelatin interpenetrating polymer network theta-gels for cartilage regeneration

2015 ◽  
Vol 3 (48) ◽  
pp. 9242-9249 ◽  
Author(s):  
Tianxin Miao ◽  
Emily Julia Miller ◽  
Canaan McKenzie ◽  
Rachael Ann Oldinski

Theta-gels are hydrogels that form during the solidification and phase separation of two dislike polymers, in which a low molecular weight polymer behaves as a porogen and is removed through dialysis.

1985 ◽  
Vol 18 (1) ◽  
pp. 78-83 ◽  
Author(s):  
Thomas P. Russell ◽  
G. Hadziioannou ◽  
W. Warburton

1983 ◽  
Vol 2 (5) ◽  
pp. 161-178 ◽  

Polyquaternium-11 is a quaternized copolymer of vinylpyrrolidone and di-methylamine ethylmethacrylate, and is used at concentrations up to 50% in a variety of hair care preparations. The acute oral LD50 in test animals of high molecular weight Polyqua-ternium-11 is estimated to be greater than 12.8 g/kg; the LD50 for the low molecular weight polymer is calculated to be 6.2 g/kg. At concentrations of up to 50% in water, the raw ingredient produced no signs of skin or eye irritation. There was no evidence of dermal toxicity in subchronic tests nor in a maximization test for sensitization. In clinical studies, 1 of 19 subjects showed slight skin irritation after a 24-hour single insult skin patch with 9.5% Polyquaternium-11 in water. Repeated insult patch tests at concentrations up to 50% produced no instances of skin sensitization and only isolated instances of transient skin irritation. Clinical photoreactivity studies on both low and high molecular weight polymers showed no evidence of phototoxicity or photoallergenicity. From the available information, it is concluded that Polyquaternium-11 is safe as a cosmetic ingredient in the present practices of use.


Soft Matter ◽  
2013 ◽  
Vol 9 (13) ◽  
pp. 3578 ◽  
Author(s):  
Maxim V. Gorkunov ◽  
Georgiy A. Shandryuk ◽  
Alina M. Shatalova ◽  
Irina Yu. Kutergina ◽  
Alexey S. Merekalov ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Susan D’Souza ◽  
Jabar A. Faraj ◽  
Stefano Giovagnoli ◽  
Patrick P. DeLuca

The aim of this study was to prepare injectable depot formulations of Olanzapine using four poly(D,L-lactide-co-glycolide) (PLGA) polymers of varying molecular weight and copolymer composition, and evaluate in vivo performance in rats. In vivo release profiles from the formulations were governed chiefly by polymer molecular weight and to a lesser extent, copolymer composition. Formulations A and B, manufactured using low molecular weight PLGA and administered at 10 mg/kg dose, released drug within 15 days. Formulation C, prepared from intermediate molecular weight PLGA and administered at 20 mg/kg dose, released drug in 30 days, while Formulation D, manufactured using a high molecular weight polymer and administered at 20 mg/kg dose, released drug in 45 days. A simulation of multiple dosing at 7- and 10-day intervals for Formulations A and B revealed that steady state was achieved within 7–21 days and 10–30 days, respectively. Similarly, simulations at 15-day intervals for Formulations C and D indicated that steady state levels were reached during days 15–45. Overall, steady state levels for 7-, 10-, or 15-day dosing ranged between 45 and 65 ng/mL for all the formulations, implying that Olanzapine PLGA microspheres can be tailored to treat patients with varying clinical needs.


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