Thermosensitive Material

A biodegradable copolymer has been described that consists of an amphiphilic diblock copolymer, of a hydrophilic segment and a hydrophobic segment (8). 

2-Thioxo-4-thiazolid inecarboxylic acid mPEG-PTTLA 

There is no coupling agent between the hydrophilic and hydrophobic segments. The pol5mer is formed by a one-pot ringopening pol5meiization technique (8). 

The pol5mer can be dissolved in water to form a thermosensitive material having a phase transfer temperature of 25-50 C. 

It can be used for biological activity factor delivery, tissue engineering, ceU culture and as a biological glue. 

---

Shulyak, V.A. and Berezyuk, D.1.1998. Method for drying of thermosensitive materials. Russian Patent 2,110,025. 

The critical temperature of supercritical CO2 (SC-CO2) is as low as 31.1°C, which can be suitable for thermosensitive materials to avoid possible thermal degradation... 

DLS is also useful for determining phase behavior and micelle formation in block copolymers dissolved in ILs. The work by Lee et al. with poly(ethylene oxide)-h-poly(A-isopropylacrylamide) (PEO-h-PNIPAM) in [C2CjIM][BF ] and [C CjIM][BFJ shows how the lower critical solution temperature (LCST) behavior of PEO and the upper critical solution temperature (UCST) behavior of PNIPAM can be exploited to form PNIPAM-core micelles at low temperature and PEO-core micelles at high temperature. As can be seen in Figure 2.15, this system is thermally reversible allowing for potential applications as thermosensitive materials [8]. 

After impingement in the middle zone of the dryer, the airstream carrying dry, powdery material is directed to the separation system. Due to intensive evaporation in the impingement zone the inlet air temperature of about 150 C falls rapidly to about 70 C, which allows drying of thermosensitive materials like antibiotics or microorganisms. At this inlet air temperature... 

Tatykhanova GS, Kudaibergenov SE. (2008) Controlled release of local anesthetic drug richlocaine from the pH- and thermosensitive hydrogels-copolymers of N-isopropylacrilamide and acrylic acid. New smart materials via metal mediated macromolecular engineering from complex to nanostructures. Antalya, Turkey, 1-12 September 2008. 

Review C.J. Hawker, J.M.J. Frechet, Step-Growth-Polymers for High Performance Materials (Eds. J.L. Hedrick, J.W. Labadie), Oxford Press, Oxford 1996, Chapter 7 M. Seiler, Chem. Eng. Technol. 2002, 3, 237—253 comparison of thermosensitivity properties of POPAM den-drimers and linear analogues Y. Haba,... 

C. Alexander, D. Gorecki, and P. Caliceti. Physico-Chemical and Pharmacokinetic Studies of Avidin Bioconjugates with Thermosensitive Polymers, 5th International Symposium on Controlled Release of Bioactive Materials, June 21-24, 1998,... 

The operating principle of such devices relies on materials whose volume changes abruptly, i.e., that display a volume phase transition (VPT), when an appropriate stimulus is applied. Thermosensitive poly(N-isopropylacrylamide) (PNIPA) hydrogel, where the cross-links are chemical, namely peptide bonds, is widely used for this purpose since its VPT in pure water is close to 34°C.1 3... 

Thermosensitive polyphosphazene polymers have been prepared by reacting poly-dichlorophosphazene with methoxypolyethylene glycol and isoleucineethyl ester. These materials are suitable for use as injectable thermosensitive biodegradable drug delivering system that have sol-gel behavior near human body temperature. 

Feil H, Bae YH, Feijen J, Kim SW. Mechanism of solute diffusion in thermosensitive hydrogels. In Proceedings of the 18th International Symposium on the Controlled Release of Bioactive Materials Lee VHL, Ed CRC Inc Lincolnshire, IL, 1991 142. 

The technology of supercritical fluids leads to a series of innovations that enhance the performance of traditional drying processes dealing with thermosensitive and sticky materials. 

Matsumaru, Y., Hyodo, A., Nose, T., Ito, S., Hirano, T. Ohashi, S. (1996) Application of thermosensitive polymers as a new embolic material for intravascular neurosurgery. Journal of Biomaterials Science — Polymer Edition, 1, 795-804. 

Henderson, E. et al, 2009. In vivo evaluation of injectable thermosensitive polymer with time-dependent LCST. Journal of Biomedical Materials Research Part A, 90A(4), 1186-1197. 

---