A copolymer based on dimethyl carbonate and a method of preparing the same are provided. The copolymer based on dimethyl carbonate has a unit from dimethyl carbonate, diols, and a modification monomer. The copolymer based on dimethyl carbonate can be obtained by proceeding transesterification and polycondenastion.

The invention generally relates to functional polymers and hydrogels. More particularly, the invention provides versatile monomers and polymers with well-defined functionalities, e.g., polycarbonates and poly(ester-carbonates), compositions thereof, and methods for making and using the same. The invention also provides cytocompatible poly(ethylene glycol)-co-polycarobonate hydrogels (e.g., crosslinked by copper-free, strain-promoted click chemistry).

Gel-forming block copolymers were prepared comprising i) a central hydrophilic block consisting essentially of a divalent poly(ethylene oxide) chain and ii) two peripheral monocarbonate or polycarbonate hydrophobic blocks linked to the central block by linking groups bearing one or more hydrogen bond forming *N(H)* groups. The hydrophobic blocks comprise one or more vitamin-bearing subunits. The gel-forming block copolymers can be used to prepare various biodegradable and/or biocompatible hydrogel and organogel drug compositions, in particular antimicrobial and/or anti-tumor drug compositions. The hydrogel compositions have utility in depot injections for drug delivery. The hydrogen bonding *N(H)* group(s) provide longer in vivo lifetime of the hydrogel before degradation and a more prolonged and controlled release rate of a hydrophobic drug compared to similar hydrogels prepared from poly(ethylene glycol).

A Process for the preparation of a functionalized terpolymer having general formula (I):

##STR00001##

and including the following steps: i) reacting at least one first epoxy compound having general formula (II):

##STR00002## with at least a second epoxy compound having general formula (III):

##STR00003## ii) reacting the terpolymer obtained in step i) with at least one sulphur-containing compound having general formula (IV):

##STR00004## provided that in the general formula (IV) at least one of between R.sub.5, R.sub.6 and R.sub.7 differs from hydrogen and at least one of between R.sub.5, R.sub.6 and R.sub.7, contains one of the following functional groups: COOH, COO.sup.M.sup.+, SO.sub.3H, SO.sub.3.sup.M.sup.+, SO.sub.2H, SO.sub.2.sup.M.sup.+, OPO.sub.3H.sub.2, OPO.sub.3.sup.2M.sup.+.sub.2, PO.sub.3H.sub.2, PO.sub.3.sup.2M.sup.+.sub.2, OH,

The above process allows for terpolymers to be obtained which are soluble in polar solvents such as, for example, water, methanol, ethanol, butanol, acetone or dimethyl sulfoxide. The terpolymers can be advantageously used, for example, as additives for cements.

Gel-forming block copolymers were prepared comprising i) a central hydrophilic block consisting essentially of a divalent poly(ethylene oxide) chain and ii) two peripheral monocarbonate or polycarbonate hydrophobic blocks linked to the central block by linking groups bearing one or more hydrogen bond forming *N(H)* groups. The hydrophobic blocks comprise one or more vitamin-bearing subunits. The gel-forming block copolymers can be used to prepare various biodegradable and/or biocompatible hydrogel and organogel drug compositions, in particular antimicrobial and/or anti-tumor drug compositions. The hydrogel compositions have utility in depot injections for drug delivery. The hydrogen bonding *N(H)* group(s) provide longer in vivo lifetime of the hydrogel before degradation and a more prolonged and controlled release rate of a hydrophobic drug compared to similar hydrogels prepared from poly(ethylene glycol).

The invention generally relates to functional polymers and hydrogels. More particularly, the invention provides versatile monomers and polymers with well-defined functionalities, e.g., polycarbonates and poly(ester-carbonates), compositions thereof, and methods for making and using the same. The invention also provides cytocompatible poly(ethylene glycol)-co-polycarobonate hydrogels (e.g., crosslinked by copper-free, strain-promoted click chemistry).

The present invention provides a polymer, preferably a degradable polymer, derived from monomers (A) and (B) and/or comprising a repeat unit of formula (Ii) and at least one terminal group of formula (II).

The present invention provides a copolymer, preferably a degradable copolymer, comprising at least first and second repeat units and/or derived from at least first, second, and third monomers.

A polycarbonate resin composition or a copolymer, comprising, as main repeating units, a carbonate unit (a-1) having a fluorene ring in a side chain, a carbonate unit (a-2) represented by the following formula (a-2): ##STR00001##
(wherein W represents an alkylene group having 1 to 20 carbon atoms or a cycloalkylene group having 6 to 20 carbon atoms, R represents a branched or linear-chain alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 6 to 20 carbon atoms optionally having a substituent, and u represents an integer of 0 to 3), and a carbonate unit (a-3) derived from 2,2-bis(4-hydroxyphenyl)propane, wherein 1) a molar ratio of the carbonate unit (a-1) to the carbonate unit (a-2) is from 50/50 to 80/20, and 2) a molar ratio of the total of the carbonate unit (a-1) and the carbonate unit (a-2) to the carbonate unit (a-3) is from 1:99 to 70:30. This polycarbonate resin composition or copolymer has excellent heat resistance, transparency, and bending resistance and has low retardation.

There are provided herein, inter alia, complexes, compositions and methods for the delivery of nucleic acid into a cell in vivo. The complexes, compositions and methods may facilitate complexation, protection, delivery and release of oligonucleotides and polyanionic cargos into target cells, tissues, and organs both in vitro and in vivo.