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OBJECTIVE@#To prepare customized porous silicone orbital implants using embedded 3D printing and assess the effect of surface modification on the properties of the implants.@*METHODS@#The transparency, fluidity and rheological properties of the supporting media were tested to determine the optimal printing parameters of silicone. The morphological changes of silicone after modification were analyzed by scanning electron microscopy, and the hydrophilicity and hydrophobicity of silicone surface were evaluated by measuring the water contact angle. The compression modulus of porous silicone was measured using compression test. Porcine aortic endothelial cells (PAOECs) were co-cultured with porous silicone scaffolds for 1, 3 and 5 days to test the biocompatibility of silicone. The local inflammatory response to subcutaneous porous silicone implants was evaluated in rats.@*RESULTS@#The optimal printing parameters of silicone orbital implants were determined as the following: supporting medium 4% (mass ratio), printing pressure 1.0 bar and printing speed 6 mm/s. Scanning electron microscopy showed that the silicone surface was successfully modified with polydopamine and collagen, which significantly improved hydrophilicity of the silicone surface (P < 0.05) without causing significant changes in the compression modulus (P > 0.05). The modified porous silicone scaffold had no obvious cytotoxicity and obviously promoted adhesion and proliferation of PAOECs (P < 0.05). In rats bearing the subcutaneous implants, no obvious inflammation was observed in the local tissue.@*CONCLUSION@#Poprous silicone orbital implants with uniform pores can be prepared using embedded 3D printing technology, and surface modification obviously improves hydrophilicity and biocompatibility of the silicone implants for potential clinical application.
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Animals , Rats , Swine , Silicon , Orbital Implants , Endothelial Cells , Porosity , Silicones , Printing, Three-DimensionalABSTRACT
The development of multifunctional nanocontrast agents with high sensitivity, high specificity, and low toxicity so that they can precisely localize tumors and reflect tumor biological information in real time is the core of promoting the development of tumor molecular imaging technology and realizing early and precise tumor diagnosis. Polydopamine (PDA) nanomaterials are bionanomaterials with a structure extremely similar to that of natural melanin. They can be easily fabricated and functionalized, and can achieve controlled assembly of functional molecules such as contrast components and targeting ligands via metal coordination, π-π stacking, electrostatic adsorption, and other methods. They have good biocompatibility and biodegradability, show great potential for clinical translation, and have been widely used in molecular imaging of tumors. In this review paper, the preclinical studies of PDA nanoparticles are reviewed as well as the synthesis methods, functionalized modification, and assembly strategies of PDA nanoparticles and their applications in tumor molecular imaging. The development trends of PDA are also presented to promote their application in the field of tumor molecular imaging.
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Objective:To investigate the adhesion of polydopamine-modified collagen membrane composites to cartilage tissues and the effect on chondrocyte proliferation, and further explore the possibility of their application in autologous chondrocyte transplantation.Methods:Porous collagen membranes were prepared, and the polydopamine-modified collagen membrane composites were constructed by the adsorption method. The physical and chemical properties and structural characteristics of the membranes, such as thermal stability, thermal properties, porous structure, and surface element composition, were characterized by infrared spectroscopy, thermogravimetric analysis, differential thermal analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. The adhesion between the polydopamine-modified collagen membrane and fresh cartilage tissue was tested by a mechanical testing machine. The effects of the membranes on the adhesion and proliferation of rabbit chondrocytes were investigated by in vitro cell culture.Results:The structure and surface element composition of the membranes altered with the increase in the adsorption time of polydopamine, and the capacity of polydopamine increased with the increase in the adsorption time. The thermal stability and thermal properties of collagen membrane materials were not significantly affected by the adsorption of polydopamine. The adhesion of the membrane to cartilage tissue increased with the increase in the amount of absorbed polydopamine. The membranes showed a time-dependent promoting effect on the proliferation of the chondrocytes.Conclusions:The polydopamine-modified collagen membrane has potential application in articular cartilage repair, but more research is required to optimize the membrane before it is used in articular cartilage repair.
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Polydopamine (PDA) is a novel type of polymer synthesized inspired by adhesion proteins in mussels. It has been widely used in tumor-targeting drug delivery systems due to its natural advantages such as good biocompatibility, excellent photothermal conversion performance, adhesion, high chemical reactivity and multiple drug release response mechanisms. This review summarizes the applications of PDA-based tumor-targeting drug delivery in recent years, hoping to provide references for designing a more reasonable and effective PDA-based multifunctional collaborative tumor therapy platform.
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Objective@#To investigate the inhibitory effect of polydopamine (PDA) on enamel demineralization in isolated teeth and the induction of hydroxyapatite (HA) production on the surface of demineralized enamel to provide a novel protocol for the prevention and treatment of enamel demineralization. @*Methods@#Twenty isolated bovine teeth were cut into 20 enamel slices and randomly divided into an experimental group and a control group, with 10 slices in each group. The enamel slices in the experimental group were immersed in 2 mg/mL freshly prepared dopamine solution and incubated for 24 hours at room temperature in the dark to prepare the PDA coating, while the control group was left untreated. Then, the isolated bovine teeth, with and without PDA coating, were immersed in artificial demineralization solution at 37 °C for 3 days, followed by 7 days in simulated body fluid (SBF), and the immersion solution was changed daily. The surface morphology of enamel was observed by scanning electron microscopy (SEM), the calcium/phosphorus ratio of the enamel surface was analyzed by energy dispersive spectroscopy (EDS), and the characteristic functional groups in enamel deposits were analyzed by Fourier transform infrared spectroscopy (FTIR).@* Results@#Compared with the control group, the number of demineralized pores produced after 3 d of enamel demineralization with polydopamine coating was less, and the diameter was smaller. EDS elemental analysis showed that the Ca/P ratio after enamel demineralization was 2.37 in the experimental group, which was smaller than the 2.53 ratio in the control group. In the remineralization experiment, after 7 days of remineralization of PDA coated enamel in the experimental group, lamellar grains were produced on the enamel surface, and the growth showed obvious directionality, growth regularity and uniform arrangement. In the control group, the surface of enamel was flocculent mineral deposit, and the crystallinity was poor. The FTIR results proved that the enamel surface deposit of PDA-coated enamel was HA after 7 d of remineralization. @*Conclusion @#PDA can affect the nucleation process of HA and promote the production of HA on the surface of demineralized enamel.
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Photothermal therapy has been intensively investigated for treating cancer in recent years. However, the long-term therapeutic outcome remains unsatisfying due to the frequently occurred metastasis and recurrence. To address this challenge, immunotherapy has been combined with photothermal therapy to activate anti-tumor immunity and relieve the immunosuppressive microenvironment within tumor sites. Here, we engineered silica-based core‒shell nanoparticles (JQ-1@PSNs-R), in which silica cores were coated with the photothermal agent polydopamine, and a bromodomain-containing protein 4 (BRD4) inhibitor JQ-1 was loaded in the polydopamine layer to combine photothermal and immune therapy for tumor elimination. Importantly, to improve the therapeutic effect, we increased the surface roughness of the nanoparticles by hydrofluoric acid (HF) etching during the fabrication process, and found that the internalization of JQ-1@PSNs-R was significantly improved, leading to a strengthened photothermal killing effect as well as the increased intracellular delivery of JQ-1. In the animal studies, the multifunctional nanoparticles with rough surfaces effectively eradicated melanoma via photothermal therapy, successfully activated tumor-specific immune responses against residual tumor cells, and further prevented tumor metastasis and recurrence. Our results indicated that JQ-1@PSNs-R could serve as an innovative and effective strategy for combined cancer therapy.
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Radiation therapy is an effective method to kill cancer cells and shrink tumors using high-energy X-ray or γ-ray. Radiation pneumonitis (RP) is one of the most serious complications of radiation therapy for thoracic cancers, commonly leading to serious respiratory distress and poor prognosis. Here, we prepared curcumin-loaded mesoporous polydopamine nanoparticles (CMPN) for prevention and treatment of RP by pulmonary delivery. Mesoporous polydopamine nanoparticles (MPDA) were successfully synthesized with an emulsion-induced interface polymerization method and curcumin was loaded in MPDA via π‒π stacking and hydrogen bonding interaction. MPDA owned the uniform spherical morphology with numerous mesopores that disappeared after loading curcumin. More than 80% curcumin released from CMPN in 6 h and mesopores recovered. CMPN remarkably protected BEAS-2B cells from γ-ray radiation injury by inhibiting apoptosis. RP rat models were established after a single dose of 15 Gy 60Co γ-ray radiation was performed on the chest area. Effective therapy of RP was achieved by intratracheal administration of CMPN due to free radical scavenging and anti-oxidation ability, and reduced proinflammatory cytokines, high superoxide dismutase, decreased malondialdehyde, and alleviated lung tissue damages were observed. Inhaled CMPN paves a new avenue for the treatment of RP.
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BACKGROUND: Recently, most studies have combined tissue engineering materials with stem cells or factors to improve the microenvironment of animal models of spinal cord injury to increase the duration of action, improve the recovery effect and prognosis. OBJECTIVE: To investigate the effect of sonic hedgehog-polydopamine-fibrin scaffold on the repair of spinal cord injury in rats. METHODS: Fibrin glue was made using a vacuum freeze-dryer. The prepared fibrin glue was immersed in a dopamine hydrochloride solution for 24 hours for cross-linking. Then the cross-linked scaffold was placed in a factor solution for adsorption and cross-linking for 24 hours. Sonic hedgehog-polydopamine-fibrin scaffolds were prepared. Sixty female SD rat models of spinal cord injury were established and then divided into four groups: In the group A, no material was implanted. In the groups B, C and D, fibrin scaffolds, polydopamine-fibrin scaffolds, and sonic hedgehog-polydopamine-fibrin scaffolds were implanted respectively. The Basso, Beattie and Bresnahan (BBB) locomotor scale score of lower limb locomotor function was evaluated within 12 weeks after surgery. At 12 weeks post-surgery, the tissue at the site of spinal cord injury was collected for histological observation (hematoxylin-eosin and immunohistochemical staining) and western blot assay. This study was approved by the Animal Ethics Committee of Jiangsu University, China. RESULTS AND CONCLUSION: (1) From 2 weeks after surgery, the lower limb locomotor function of rats in each group began to recovery. At 5-12 weeks after surgery, the BBB score of group D was significantly higher than that of the other three groups (P < 0.05). Rats in group D had the best recovery of locomotor function of the lower limb. (2) Hematoxylin-eosin staining revealed newly generated nerve fibers in the groups C and D, and that the number of density of new nerve fibers in group C was lower than that in group D. (3) Immunohistochemical staining showed that a large amount of linearly arranged new nerve fibers were observed in the completely transected site of rat spinal cord. In group D, myelin basic protein-, growth related protein- and neurofilament protein-positive rates were significantly higher (P < 0.05), and glial fibrillary acidic protein-positive rate was significantly lower, compared with the other three groups. (4) Western blot assay revealed that in group D, the protein expression of myelin basic protein, growth related protein and neurofilament protein was significantly higher (P < 0.05), and the protein expression of glial fibrillary acidic protein was significantly lower (P < 0.05), compared with the other three groups. (5) These results suggest that sonic hedgehog-polydopamine-fibrin has a good sustained-release performance, which can greatly promote the repair of spinal cord injury in rats.
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Objective: Using polydopamine (PDA) as a carrier to construct a Salviae Miltiorrhizae Radix et Rhizoma (SMRR) nano-delivery system (PDA-SMRR), which can load a large number of SMRR water-soluble components and better exert antioxidation and antistress effect. Methods: PDA-SMRR nanoparticles (PDA-SMRR) were prepared, and the prescription process was investigated and optimized by single-factor experiments. The particle size, potential, and morphology of the nanoparticles were examined by a laser particle size analyzer and a transmission electron microscope. The drug loading and cumulative release rate were analyzed by dialysis. The cardiomyocytes of neonatal rats were extracted and cultured. The CCK-8 experiment was used to investigate the biological safety of PDA-SMRR and verify the protective effect of PDA-SMRR on oxidative stress-induced cardiomyocytes. Results: The optimal drug loading process was pH value 3.5, drug loading time was 12 h, drug loading temperature was room temperature, and PDA-SMRR was successfully prepared. The morphology and size of the nanoparticles were regular and uniform. The particle size and Zeta potential were (459.2 ± 4.5) nm, (3.01 ± 0.3) mV; In vitro release experiments indicated that SMRR was released slowly by the delivery system. CCK-8 experiments showed that PDA-SMRR had good biological safety and nanoparticles can reduce damaged cardiomyocytes caused by oxidative stress. Conclusion: PDA-SMRR can be used as a multi-component medicine depot for SMRR, with high drug loading and sustained release effect, which can effectively reduce the damage of oxidative damage on myocardial cells.
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Conjugation of antibodies to nanoparticles allows specific cancer targeting, but conventional conjugation methods generate heterogeneous conjugations that cannot guarantee the optimal orientation and functionality of the conjugated antibody. Here, a molecular engineering technique was used for site-specific conjugation of antibodies to nanoparticles. We designed an anti-claudin 3 (CLDN3) antibody containing a single cysteine residue, h4G3cys, then linked it to the maleimide group of lipid polydopamine hybrid nanoparticles (LPNs). Because of their negatively charged lipid coating, LPNs showed high colloidal stability and provided a functional surface for site-specific conjugation of h4G3cys. The activity of h4G3cys was tested by measuring the binding of h4G3cys-conjugated LPNs (C-LPNs) to CLDN3-positive tumor cells and assessing its subsequent photothermal effects. C-LPNsspecifically recognized CLDN3-overexpressing T47D breast cancer cells but not CLDN3-negative Hs578T breast cancer cells. High binding of C-LPNs to CLDN3-overexpressing T47D cells resulted in significantly higher temperature generation upon NIR irradiation and potent anticancer photothermal efficacy. Consistent with this, intravenous injection of C-LPNsin a T47D xenograft mouse model followed by NIR irradiation caused remarkable tumor ablation compared with other treatments through high temperature increases. Our results establish an accurate antibody-linking method and demonstrate the possibility of developing therapeutics using antibody-guided nanoparticles.
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Objective: To coat polydopamine (PDA) on the surface of biphasic calcium phosphate (BCP) scaffold prepared by 3D printing and construct a novel bone tissue engineering scaffold with high osteogenic activity, and to conduct a preliminary evaluation on its application potential.Methods:BCP bioceramic scaffolds were prepared by 3D printing technology, and then they were immersed in dopamine solution for a certain period to form a nanoscale PDA film structure on the surface.The PDA-free scaffolds were named 3DBCP group, and the PDA-coated scaffolds were named PDA-3DBCP group. Scanning electron microscope (SEM) was used to observe the surface topography of the scaffolds in each group; the hydrophilicity of the material was characterized by measuring the water contact angle of the scaffold surface; the scaffold porosity was determined by the specific gravity method, and the mechanical strength was tested by the universal testing machine; CCK-8 assay was adopted to detect the cell proliferation activity on the scaffold.Results:Compared with 3DBCP group, the surface water contact angle of the the scaffolds in PDA-3DBCP group was significantly reduced (t=5.06,P0.05;t=0.002,P>0.05).The cells were inoculated into the scaffolds and cultured for 1, 3 and 5 d;the CCK-8 assay results showed that the proliferation activities of the cells in two groups were gradually increased with the prolongation of the culture time. Furthermore, compared with 3DBCP group, the cell proliferation activity of the cells in PDA-3DBCP group on the 5th day was significantly increased (t=39.3,P<0.05).Conclusion: The PDA-coated 3D printed BCP porous scaffold has the advantages in characterization,it can improve the cell proliferation ability, which shows the potential as bone tissue engineering scaffolds.
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An ultrasensitive electrochemical sensor based on polydopamine/carboxylic multi-walled carbon nano-tubes (MWCNTs-COOH) nanocomposites modified glassy carbon electrode (GCE) was presented in this work, which has been developed for highly selective and highly sensitive determination of an anti-microbial drug, metronidazole. The preparation of polydopamine/MWCNTs―COOH nanocomposites/GCE sensor is simple and possesses high reproducible, where polydopamine can be coated on the surface of MWCNTs―COOH via a simple electropolymerization process. Under optimized conditions, the proposed sensor showed ultrasensitive determination for metronidazole with a wide linear detection range from 5 to 5000μmol/dm3 and a low detection limit of 0.25μmol/dm3 (S/N = 3). Moreover, the proposed sensor has been successfully applied for the quantitative determination of metronidazole in real drug samples. This work may provide a novel and effective analytical platform for determination of me-tronidazole in application of real pharmaceutical and biological samples analysis.
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Screening aptamers using nano-materials ( such as graphene oxide, gold nanoparticle, carbon nano-tube, etc. ) that can quench fluorescence and absorb single stranded DNA using hydrogen bond, π-πbond, charge transfer, and other non-covalent ways to combine with ssDNA, but without other conformational DNA, can excellently separate specific aptamers from non-specific ones. In this case, we can shorten the cycle numbers, enhance the success rate, and reduce the labour intensity of systematic evolution of ligands by exponential enrichment ( SELEX) . Especially for small molecular target, due to its difficulty in immobilization and small size, it is difficult to use traditional methods such as SPR-SELEX or affinity-SELEX for screening. In this experiment, polydopamine nanospheres ( MNPs@PDAs) were used to screen the Lomefloxacin. Also, we used magnetic separation technique to screen small molecular target rapidly. The interaction between aptamer candidates and the target could be monitored by recovery ratio of ssDNA and the whole MNPs@PDAs-SELEX process was performed through seven-round selection. As a result, we successfully obtained the aptamer named AF-3 which could recognize the lomefloxacin with high affinity (KD=(17. 57±0. 5) nmol/L). This screening method based on MNPs@PDAs makes it a promising reagent in the efficient aptamers selection of other targets.
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Objective To prepare docetaxel (DTX) loaded active breast cancer-targeted pH-responsive nanoparticles and to determine its chemo-physical properties, drug loading and releasing characteristics, and targeting ability and cytotoxity against MCF-7 cells. Methods The nanoparticles were synthesized by nanoprecipitation method and surface modification based on polydopamine (PDA). The morphology, size and zeta potential, and surface modification of the nanoparticles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray photoelectron spectroscopy (XPS). respectively. Drug loading content, encapsulation efficiency, and in vitro drug release profiles were measured by dialysis and high performance liquid chromatography (HFLC). The in vitro cellular uptake was analyzed by confocal laser scanning microscope (CLSM) and flow cytometry (FCM), and the the effect of drug-loaded nanoparticles on the viability of MCF-7 cells was determined by MTT assays. Results The DTX loaded nanoparticles, CA-PIGA@PDA-PEG-FA/NPs, exhibited a core-shell structure, with hydrodynamic size of (166. 4 ± 3. 9) nm, zeta potential of (- 11. 7±3. 8) mV, drug loading efficiency of (9. 67 ±0. 45)%, and encapsulation efficiency of (88. 32±3. 10)%. Furthermore, the drug release rate of the nanoparticles in pH 5. 0 release medium was faster than that in pH 7. 4. XPS spectra showed that PDA and folic acid were modified on the surface of the nanoparticles. The active targeting nanoparticles ingested by MCP-7 cells were more than the nanoparticles not linked to active targeting ligands, and the cytotoxicity of active-targeted nanoparticles was significantly superior than that of Taxotere® (clinical preparation of DTX). Conclusion The active breast cancer targeted pH responsive nanoparticles (DTX-loaded CA-PLGA@ PDA-PEG-FA/NPs) exhibits promising targeting ability and efficient antitumor activity in vitro against MCF-7 cells.
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Objective Carbon/carbon ( C/C) composites are a potential material for bone repair .To improve the hydrophilicity and biological activity of C/C composites , polydopamine coating was prepared on the surface of C /C composites.Methods By changing the coating time and coating environment ( oxygen or air atmosphere ), a series of polydopamine coating samples were prepared . The water contact angle test , scanning electron microscope , energy dispersive spectrometer , atomic force microscope and protein adsorption test were used to characterize the properties of different samples.Then, the data were analyzed to optimize preparation conditions .Results When the concentration of dopamine was 2.0 g/L,and the coating time was 30 min (oxygen atmosphere) +11.5 h (air atmosphere), the water contact angle was decreased from 64.0°(blank sample) to 25.9°, suggesting that the hydrophilicity was improved greatly . The results of the scanning electron microscope , energy dispersive spectrometer and atomic force microscope showed that the coating was uniform and dense .The amount of protein adsorption per sample was 0.2817 mg.Conclusion The polydopamine coating on the C/C composites improves its hydrophilicity and biological activity , which indicates that the polydopamine coated C/C composites will be a new potential material for bone tissue repair .
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Objective:To evaluate the micro-push-out bond strengths of prefabricated glass fiber posts with poly-dopamine functionalized to root dentin using resin cements, contrasted with silane treatment. Methods:In the study, 30 glass fiber posts were randomly divided into 3 groups ( 10 posts in each group) for different surface treatments. Group 1, treated with poly-dopa; Group 2, treated with silane coupling agent for 60s;Group 3, no surface treatment (Control group). The 30 extracted human, single-rooted teeth were endodontically treated and a 9 mm post space was prepared in each tooth with post drills provided by the manufacturer. Following post cementation, the specimens were stored in distilled water at 37 ℃ for 7 days. The micro-push-out bond strengths were tested using a universal testing machine (0. 5 mm/min), and the failure modes were examined with a stereomicroscope. The data of the three groups were statistically analyzed using the one-way ANOVA test(α= 0. 05). Results:The bond strengths were (7. 909 ± 1. 987) MPa for Group 1, (5. 906 ± 0. 620) MPa for Group 2, and 4. 678 ± 0. 910 MPa for Group 3 . The bond strength of poly-dopamine group was significantly higher than that of the silane group (P<0. 05). Conclusion: Contrasted with silane treatment, surface poly-dopamine functionaliza-tion was confirmed to be a more reliable method for improving the bond strength of resin luting agents to fiber posts.