Publications by authors named "Qing-Fa Guo"

Chronic pain is often accompanied by tissue damage and pain hypersensitivity. It easily relapses and is challenging to cure, which seriously affects the patients' quality of life and is an urgent problem to be solved. Current treatment methods primarily rely on morphine drugs, which do not address the underlying nerve injury and may cause adverse reactions.

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In this study, superparamagnetic iron oxide (SPIO) nanoparticles (NPs) with an average size of 10±2 nm were coated with doxorubicin (Dox)-conjugated heparin (DH-SPIO) and were used for targeted anticancer drug delivery, and as a magnetic resonance imaging (MRI) contrast agent. The DH-SPIO NPs had a mean particle size of 125±10 nm and a zeta potential of –35±3 mV. Fourier transform-infrared spectroscopy, X-ray diffraction spectroscopy, transmission electron microscopy, vibrating sample magnetometry, and MTT assay were used to investigate the properties of DH-SPIO NPs.

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Local anti-oncogene delivery providing high local concentration of gene, increasing antitumor effect and decreasing systemic side effects is currently attracting interest in cancer therapy. In this paper, a novel local sustained anti-oncogene delivery system, PECE thermoresponsive hydrogel containing folate-poly (ester amine) (FA-PEA) polymer/DNA (tumor suppressor) complexes, is demonstrated. First, a tumor-targeted biodegradable folate-poly (ester amine) (FA-PEA) polymer based on low-molecular-weight polyethyleneimine (PEI) was synthesized and characterized, and the application for targeted gene delivery was investigated.

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Hot-melt extrusion (HME) plays an important role in preparing implants as local drug delivery systems in pharmaceutical fields. Here, a new PLA/PEG-PPG-PEG/Dexamethasone (PLA/F68/Dex) implant prepared by HME has been developed. Importantly, the implant was successfully achieved to control release of immunosuppressive drug to an implanted device.

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The corium is decreased to about half of its thickness in skin defects and wrinkles due to gravity and environment. In this study, dexamethasone/poly(d,l-lactic acid) (Mn = 160,000) microspheres were incorporated into poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (Mn = 3300) hydrogel to prepare an injectable hydrogel composite. The composite was designed to increase the thickness of the corium.

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Background: Gene therapy is a promising approach to the treatment of a wide range of diseases. The development of efficient and adequate gene delivery systems could be one of the most important factors. Polyethyleneimine, a cationic polymer, is one of the most successful and widely used vectors for nonviral transfection in vitro and in vivo.

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In this paper, we prepared a novel cationic self-assembled micelle from poly(epsilon-caprolactone)-poly(ethyl glycol)-poly(epsilon-caprolactone) grafted polyethyleneimine (PCEC-g-PEI). The PCEC-g-PEI micelles, formed by self-assembly method, had mean particle size of ca. 82 nm and zeta potential of +22.

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Rapid local transdermal anaesthetic is desirable in clinic. In this paper, lidocaine loaded poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL) nanoparticles were prepared, and a novel transdermal lidocaine formulation: lidocaine loaded PCL-PEG-PCL nanoparticles in F127 hydrogel (Nano-Lido Gel), was demonstrated. These lidocaine loaded PCL-PEG-PCL nanoparticles with mean particle size of ca.

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This paper prepared novel biodegradable and pH-sensitive microgels based on Poly(epsilon-caprolactone)-Pluronic-Poly(epsilon-caprolactone)-dimethacrylate (PCFC-DMA), Poly(ethylene glycol) dimethacrylate (PEG-DMA) and methylacrylic acid (MAA) cross-linked with N,N'-methylenebisacrylamide (BIS), initiated by NaHSO(3), K(2)S(2)O(8). The blank microgels were prepared by inversed-phase suspension polymerization method and pH sensitivity of microgels was characterized. Then the blank microgels were loaded with hydrophilic model drug vitamin-12 (VB-12) and in vitro drug release behaviour was also studied here.

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Poly(epsilon-caprolactone)-poly(ethylene glycol) (PCL-PEG) copolymers are important synthetic biomedical materials with amphiphilicity, controlled biodegradability, and great biocompatibility. They have great potential application in the fields of nanotechnology, tissue engineering, pharmaceutics, and medicinal chemistry. This review introduced several aspects of PCL-PEG copolymers, including synthetic chemistry, PCL-PEG micro/nanoparticles, PCL-PEG hydrogels, and physicochemical and toxicological properties.

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Background: Polyethyleneimine (PEI), a cationic polymer, is one of the successful and widely used vectors for non-viral gene transfection in vitro. However, its in vivo application was greatly limited due to its high cytotoxicity and short duration of gene expression. To improve its biocompatibility and transfection efficiency, PEI has been modified with PEG, folic acid, and chloroquine in order to improve biocompatibility and enhance targeting.

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It has been demonstrated that spray-drying is a powerful method to prepare dry powders for pulmonary delivery. This paper prepared dispersible dry powders based on chitosan and mannitol containing honokiol nanoparticles as model drug. The results showed that the prepared microparticles are almost spherical and have appropriate aerodynamic properties for pulmonary delivery (aerodynamic diameters was between 2.

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In this work, a biodegradable and injectable in situ gel-forming controlled drug delivery system based on thermosensitive poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCEC) hydrogel was studied. The prepared PCEC hydrogel undergoes temperature-dependent sol-gel-sol transition, which is a flowing sol at ambient temperature and turns into a non-flowing gel at around physiological body temperature. Furthermore, the sol-gel phase transition mechanism was investigated using (13)C-nuclear magnetic resonance imaging and a laser diffraction particle size analyzer.

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