One type of electroactive shape memory nanocomposite was fabricated, including cross-linked poly(ε-caprolactone) (cPCL) and conductive multiwalled carbon nanotubes (MWNTs). The cross-linking reaction of the pristine poly(ε-caprolactone) (PCL) was realized by using benzoyl peroxide (BPO) as an initiator. The raw MWNTs (Raw-M) were prefunctionalized by acid-oxidation process and covalent grafting with poly (ethylene glycol) (PEG), respectively. Three kinds of nanocomposites containing cPCL/Raw-M, cPCL/acid-oxidation MWNTs (AO-M) and cPCL/PEG grafted MWNTs (PEG-M) were obtained, and the mechanical, electrical and shape memory properties were further investigated. The influence of in vitro degradation on their shape memory and mechanical properties was also evaluated. The methyl thiazolyl tetrazolium (MTT) assay was performed to estimate their biocompatibility. The results displayed that these nanocomposites could perform favorable shape memory recovery both in hot water at 55 °C and in electric field with 50 V applied voltage. In addition, compared with cPCL/Raw-M and cPCL/AO-M, cPCL/PEG-M composite possessed more favorable properties such as mechanical, biocompatible, and electroactive shape memory functions. Therefore, the nanocomposite may be potential for application as smart bioactuators in biomedical field.
Acute liver injury (ALI) has an elevated fatality rate due to untimely and ineffective treatment. Although, schisandrin B (SchB) has been extensively used to treat diverse liver diseases, its therapeutic efficacy on ALI was limited due to its high hydrophobicity. Palmitic acid-modified serum albumin (PSA) is not only an effective carrier for hydrophobic drugs, but also has a superb targeting effect via scavenger receptor-A (SR-A) on the M1 macrophages, which are potential therapeutic targets for ALI. Compared with the common macrophage-targeted delivery systems, PSA enables site-specific drug delivery to reduce off-target toxicity. Herein, we prepared SchB-PSA nanoparticles and further assessed their therapeutic effect on ALI. In vitro, compared with human serum albumin encapsulated SchB nanoparticles (SchB-HSA NPs), the SchB-PSA NPs exhibited more potent cytotoxicity on lipopolysaccharide (LPS) stimulated Raw264.7 (LAR) cells, and LAR cells took up PSA NPs 8.79 times more than HSA NPs. As expected, the PSA NPs also accumulated more in the liver. Moreover, SchB-PSA NPs dramatically reduced the activation of NF-κB signaling, and significantly relieved inflammatory response and hepatic necrosis. Notably, the high dose of SchB-PSA NPs improved the survival rate in 72 h of ALI mice to 75%. Hence, SchB-PSA NPs are promising to treat ALI.
We present a vision and language model named MultiModal-GPT to conduct multi-round dialogue with humans. MultiModal-GPT can follow various instructions from humans, such as generating a detailed caption, counting the number of interested objects, and answering general questions from users. MultiModal-GPT is parameter-efficiently fine-tuned from OpenFlamingo, with Low-rank Adapter (LoRA) added both in the cross-attention part and the self-attention part of the language model. We first construct instruction templates with vision and language data for multi-modality instruction tuning to make the model understand and follow human instructions. We find the quality of training data is vital for the dialogue performance, where few data containing short answers can lead the model to respond shortly to any instructions. To further enhance the ability to chat with humans of the MultiModal-GPT, we utilize language-only instruction-following data to train the MultiModal-GPT jointly. The joint training of language-only and visual-language instructions with the \emph{same} instruction template effectively improves dialogue performance. Various demos show the ability of continuous dialogue of MultiModal-GPT with humans. Code, dataset, and demo are at https://github.com/open-mmlab/Multimodal-GPT
9-[P-(N,N-dipropylsulfamide)]benzoylamino-1,2,3,4-4H-acridine (PTHA) was synthesized as a prodrug to improve the curative effect of tacrine hydrochloride (THA), to prolong the activation time in brain, and to decrease the hepatic toxicity. The prodrug was prepared by attaching carboxyl group of probenecid to 9-amino group of THA. The structure of PTHA was confirmed by IR, 1HNMR, MS and UV. The physiochemical properties and stabilities of the prodrug under various conditions were investigated. Possibility of the prodrug passing through the blood–brain barrier (BBB) was evaluated in vitro by biopartition micellar chromatography (BMC). The concentrations of THA and PTHA in various tissues were determined by reversed-phase high-performance liquid chromatography after intravenous (i.v.) administration. The results showed PTHA was stable in various pHs and temperatures. It was indicated by partition coefficient in ethyl acetate/water that lipophilicity of the prodrug increased and it was predicted by BMC that the prodrug could improve the infiltration ability across BBB of THA. In-vivo experiment showed the concentrations of THA in brain and liver kept stable for about 4 h, which was beneficial for the treatment of Alzheimer's disease (AD). Compared with THA at the same time, AUC in liver decreases significantly, the overall targeting efficiency (TE) was enhanced from 10.97 to 16.11% and AUCbrain/AUCliver increased from 1.52 to 2.53, which suggests the possibility to reduce the hepatic toxicity of THA by the way of the prodrug.
Macro-sized (centimeters long) double-walled carbon nanotube (DWNT) strands were connected by current-assisted laser irradiation after bandaging their overlapped ends with DWNT films. During the laser processing, structural transformation of DWNT bundles happened at the joints, which provided molecular bonding between the strands. Tensile tests indicate that the joints made in this way have relatively high tensile strength with a maximum value of 335.6 MPa corresponding to that of the original strands. And the electronic properties of the connected strands were not greatly weakened in our investigation on their temperature dependence of resistivity. This work may offer a promising potential for future extensive use of macro-sized carbon nanotube structures in many fields.
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