Enhanced cell affinity and osteogenic differentiation of liquid crystal-based substrate via surface bio-functionalization.

Regulation of cell-substrate interactions is an important factor for modulating cell behaviors. Tailoring the physical and chemical properties of the substrates to better mimic the extracellular matrix (ECM) of native tissue is a more effective strategy for enhancing the cell-substrate contact. In current work, we aim at improving surface bioactivity based on the liquid crystalline substrates for the enhancement in cell affinity and osteogenic differentiation. Polydopamine (PDOPA) adhesive coating was used as a reactive platform for the immobilization of chitooligosaccharide (COS) on the octyl hydroxypropyl cellulose ester (OPC) substrate to generate active OPC-PDOPA-COSs liquid crystalline substrates. Results demonstrated that PDOPA-coated OPC surfaces showed remarkably improved hydrophility and increased elastic modulus, leading to better initial cell attachment. Subsequent COS immobilization on the OPC-PDOPA layer could induce promotion of cell proliferation, polarization and cytoskeleton formation. Rat bone marrow mesenchymal stem cells (rBMSCs) seeded on the OPC-PDOPA-COSs showed higher alkaline phosphatase (ALP) activity, calcium deposition, and up-regulated bone-related genes expression, including BMP-2, RUNx-2, COL-I and OCN. In conclusion, surface biofunctionalization on the OPC-based liquid crystalline substrates could come into being the appropriate combination of surface chemistry and liquid crystalline characteristic that simulating in vivo ECM environment, resulting in a favorable support to enhance positive cell-substrate interactions.

An alginate/poly(N-isopropylacrylamide)-based composite hydrogel dressing with stepwise delivery of drug and growth factor for wound repair.

Anti-inflammation and angiogenesis play an essential role in wound healing. In this study, we developed a composite hydrogel dressing with stepwise delivery of diclofenac sodium (DS) and basic fibroblast growth factor (bFGF) in the inflammation stage and new tissue formation stage respectively for wound repair. Sodium alginate (SA) crosslinked by calcium ion acted as the continuous phase, and thermosensitive bFGF-loaded poly(N-isopropylacrylamide) nanogels (pNIPAM NGs, LCST1 ~33 °C) and DS-loaded p(N-isopropylacrylamide-co-acrylic acid) nanogels [p(NIPAM-co-AA) NGs, LCST2 ~40 °C] acted as the dispersed phase. The synthesized SA/bFGF@pNIPAM/DS@p(NIPAM-co-AA) hydrogel presented a desirable storage modulus of ~4500 Pa, a high water equilibrium swelling ratio of ~90, an appropriate water vapor transmission rate of ~2300 g/m2/day, and nontoxicity to human skin fibroblasts. The in vitro thermosensitive cargo delivery of this hydrogel showed that 92% of DS was sustainably delivered at 37 °C within the early three days mimicking the inflammation stage, while 80% of bFGF was controlled released at 25 °C within the later eight days mimicking new tissue formation stage. The in vivo wound healing of rats showed that this composite hydrogel presented a better healing effect with a wound contraction of 96% at 14 d, less inflammation and higher angiogenesis, than all control groups. These findings indicate SA/bFGF@pNIPAM/DS@p(NIPAM-co-AA) composite hydrogel is a potential dressing for wound repair.

Taxonomic studies of Glochidion (Phyllanthaceae) from the Indo-China Peninsula (II): The identities of G.anamiticum and G.annamense.

The names Glochidionanamiticum (Kuntze) Kuntze ex Merrill and G.annamense Beille were previously reduced to synonyms of G.eriocarpum Champ. ex Benth. However, literature examination and morphological comparison suggest that G.annamense is conspecific with G.anamiticum and the species can be readily distinguished from G.eriocarpum by its styles connate into a long cylindric column and up to 3 mm long, ovaries usually 3-locular, stigma usually 3-lobed, capsules pubescent and usually 6-grooved, persistent styles 3‒4 mm long. Thus, the specific status of G.anamiticum is here reinstated and G. annamense is treated as its synonym.

Taxonomic studies of Glochidion (Phyllanthaceae) from the Indo-China Peninsula (I): G. shanense, a new species from Myanmar.

Based on morphological studies performed on live plants in the field and specimens deposited in herbaria, a new species, Glochidion shanense Gang Yao & Shixiao Luo (Phyllantheae, Phyllanthaceae), is here described and illustrated. The species is morphologically most similar to G. ellipticum Wight, but can be distinguished from the latter by having hairy branchlets, longer pedicels, uniseriate and narrowly triangular sepals of female flowers, 4-5-locular ovaries, stout and cylindric persistent style on fruits.