Described herein are organoborane polymers and methods for the oxidation of these organoborane polymers to poly (vinyl alcohol) PVA. The organoborane polymers of the present invention respond to an external trigger by changing from a hydrophobic to a hydrophilic state.

Described herein are polymers, polymeric gels, or a composition thereof, for drug delivery. The polymers, which include boronic-acid containing moieties (e.g., ##STR00001##
and polyol-containing moieties (e.g., ##STR00002##
are prepared by free-radical polymerization and can self-assemble into polymeric gels such as hydrogels. Also provided are methods or preparing the polymers, kits involving the polymers and/or polymeric gels or a composition thereof, for use as materials or delivery applications of an agent to a subject.

Described herein are polymers, polymeric gels, or a composition thereof, for drug delivery. The polymers, which include boronic-acid containing moieties (e.g., ##STR00001##
and polyol-containing moieties (e.g., ##STR00002##
are prepared by free-radical polymerization and can self-assemble into polymeric gels such as hydrogels. Also provided are methods or preparing the polymers, kits involving the polymers and/or polymeric gels or a composition thereof, for use as materials or delivery applications of an agent to a subject.

Disclosed are the cation polymers capable of removing their positive charges in oxidative conditions, preparation methods, and applications as gene delivery carriers. The oxidation-responsive unit is the p-(boronic acid or ester)benzylammonium, which upon oxidation eliminates p-hydroxymethlphenol and thus converts in a tertiary amine. Compared with the prior art, different from a common quaternary amination carrier, the synthesized charge reversal type gene delivery carrier for oxidative response of the present invention has a large quantity of positive charges and can well coat a DNA, but the positive charges can be removed under the condition of intracellular oxidation when the charge reversal type gene delivery carrier enters a cell, a charge reverse is triggered, the positive charges turn to negative charges, and the DNA is quickly released for transfection. The carrier is efficient, low in toxicity, and good in application prospect.

Disclosed are the cation polymers capable of removing their positive charges in oxidative conditions, preparation methods, and applications as gene delivery carriers. The oxidation-responsive unit is the p-(boronic acid or ester)benzylammonium, which upon oxidation eliminates p-hydroxymethlphenol and thus converts in a tertiary amine. Compared with the prior art, different from a common quaternary amination carrier, the synthesized charge reversal type gene delivery carrier for oxidative response of the present invention has a large quantity of positive charges and can well coat a DNA, but the positive charges can be removed under the condition of intracellular oxidation when the charge reversal type gene delivery carrier enters a cell, a charge reverse is triggered, the positive charges turn to negative charges, and the DNA is quickly released for transfection. The carrier is efficient, low in toxicity, and good in application prospect.

The present invention provides a catalyst composition including a functionalizing agent of the following Formula 1 together with a rare earth metal compound, an alkylating agent, and a halogen compound, having good catalytic activity and polymerization reactivity and useful for the preparation of a conjugated diene-based polymer having high linearity and excellent processability, and a conjugated diene-based polymer prepared using the catalyst composition.
(X.sub.1).sub.aSn(X.sub.2).sub.4-a[Formula 1] In Formula 1, a, X.sub.1, and X.sub.2 are the same as defined in the disclosure.

Polymers derived from a metallocene comprising a group IV element and at least one cyclopentadienyl group are described. Methods for preparing refractory ceramics comprising group IV carbides and/or borides using such polymer are also disclosed. In some embodiments, the method for fabricating the refractory ceramic comprises infiltrating a fiber preform with such polymer and pyrolyzing the polymeric fiber preform.

Polymers derived from a metallocene comprising a group IV element and at least one cyclopentadienyl group are described. Methods for preparing refractory ceramics comprising group IV carbides and/or borides using such polymer are also disclosed. In some embodiments, the method for fabricating the refractory ceramic comprises infiltrating a fiber preform with such polymer and pyrolyzing the polymeric fiber preform.

Disclosed are the cation polymers capable of removing their positive charges in oxidative conditions, preparation methods, and applications as gene delivery carriers. The oxidation-responsive unit is the p-(boronic acid or ester)benzylammonium, which upon oxidation eliminates p-hydroxymethlphenol and thus converts in a tertiary amine. Compared with the prior art, different from a common quaternary amination carrier, the synthesized charge reversal type gene delivery carrier for oxidative response of the present invention has a large quantity of positive charges and can well coat a DNA, but the positive charges can be removed under the condition of intracellular oxidation when the charge reversal type gene delivery carrier enters a cell, a charge reverse is triggered, the positive charges turn to negative charges, and the DNA is quickly released for transfection. The carrier is efficient, low in toxicity, and good in application prospect.

The present invention discloses a boron-containing plastic crystal polymer and a preparation method therefor and an application thereof. The described preparation method comprises the following step: curing a mixture containing a plastic crystal, a metal salt, a monomer and a photoinitiator. The plastic crystal polymer prepared by the present invention can be used as all-solid electrolyte, without any liquid additive being added therein. The obtained electrolyte has a room-temperature ionic conductivity up to 3.6104 S/cm, and shows a high sodium ion transference number and a wide electrochemical window up to 4.7V. The present invention further prepares composite positive and negative electrodes for positive and negative electrode modification of a sodium ion battery. A finally assembled all-solid sodium ion battery shows good rate performance and cycle stability at room temperature, achieving a specific discharge capacity up to 104.8 mAh/g at room temperature and a capacity retention ratio of 85.4% after 80 cycles.