Synthesis, Self-Assembly, and Drug-Release Properties of New Amphipathic Liquid Crystal Polycarbonates

Abstract

New amphiphilic liquid crystal (LC) polycarbonate block copolymers containing side-chain cholesteryl units were synthesized. Their structure, thermal stability, and LC phase behavior were characterized with Fourier transform infrared (FT-IR) spectrum, 1H NMR, gel permeation chromatographic (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), polarizing optical microscope (POM), and XRD methods. The results demonstrated that the LC copolymers showed a double molecular arrangement of a smectic A phase at room temperature. With the elevating of LC unit content in such LC copolymers, the corresponding properties including decomposition temperature (Td), glass temperature (Tg), and isotropic temperature (Ti) increased. The LC copolymers showed pH-responsive self-assembly behavior under the weakly acidic condition, and with more side-chain LC units, the self-assembly process was faster, and the formed particle size was smaller. It indicated that the self-assembly driving force was derived from the orientational ability of LC. The particle size and morphologies of self-assembled microspheres loaded with doxorubicin (DOX), together with drug release tracking, were evaluated by dynamic light scattering (DLS), SEM, and UV–vis spectroscopy. The results showed that DOX could be quickly released in a weakly acidic environment due to the pH response of the self-assembled microspheres. This would offer a new strategy for drug delivery in clinic applications.

Stimulatory Effects of Boron Containing Bioactive Glass on Osteogenesis and Angiogenesis of Polycaprolactone: In Vitro Study

“…However, the main limitation of PCL is its relatively slow bioresorption rate in vivo [37, 43]. Moreover, the products of PCL degradation are acidic and could cause delayed aseptic inflammatory response when implanted in vivo, resulting in failure of implantation [44, 45]. The purpose of the present study is to improve the mechanical properties and degradation properties of PCL materials by B-BG composite with the contents of 0, 10, 20, 30, and 40 wt.%, respectively.…”

Functionalized Particles Designed for Targeted Delivery

“…Literature from the last ten years contains many examples of drug carriers prepared from polycarbonates and polycarbonate-containing copolymers [ 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ].…”

“…The copolymers listed in Table 1 were used for preparation of functional nanoparticles by nanoprecipitation [ 39 , 76 , 80 , 81 , 171 , 174 , 207 , 210 ], reverse nanoprecipitation [ 78 , 79 , 167 , 169 , 179 , 209 , 211 ], solvent evaporation/dialysis [ 60 , 61 , 63 , 64 , 66 , 70 , 71 , 72 , 73 , 74 , 75 , 168 , 170 , 171 , 172 , 178 , 184 , 185 , 194 ], salting-out [ 189 ], freeze-drying [ 180 , 186 ], electrospraying [ 192 , 206 ], heat-denaturation [ 190 , 196 , 198 ], and ionic gelation [ 197 ]. The nanoparticles were loaded with doxorubicin [ 60 , 64 , 66 , 71 , 72 , 74 ,…”

Current researches on design and manufacture of biopolymer-based osteochondral biomimetic scaffolds

“…Moreover, computer-aided design has been rapidly developed in order to optimize OC scaffolds with reduced design period and experimental cost. In view of processability, flexibility and cost-effectiveness, polymer-based biomaterials with good biodegradability and biocompatibility [18] have drawn our attention, particularly polymer-based nanocomposites due to the presence of inorganic nHA crystals in bone.…”