Objective To evaluate the suitability of the biodegradable microsphere encapsulation of adenovirus as a targeting vector for gene therapy of hepatocellular carcinoma. Methods Encapsulate the recombinant adenovirus in PLG 〔poly (lactic/glycolic)〕 copolymer by the solution evaporation method, the release test and the bioactivity of viruses incorporated in vitro were studied. Results More than 19.3% of adenovirus was encapsulated in PLG microspheres. The release test shows that the adenovirus was released for more than 200 h, 50% were shed within the first 100 h, and their activity was retained. Conclusion Recombinant adenovirus can be formulated in a polymer preparation of PLG with retention of bioactivity. It may be a valuable vector for the gene therapy of liver cancer.
Curcumin-loaded poly (α-isobutyl cyanoacrylate) microspheres (Cur-HP-β-CD-PiBCA) were prepared by one-step emulsification with α-isobutyl cyanoacrylate as materials, poloxamer 188 as emulsifier, and curcumin complex with hydroxypropyl-β-cyclodextrin (Cur-HP-β-CD) as drug prepared by kneading method. Effects of emulsifier and drug concentration on microspheres size and distribution, drug loading and encapsulation efficiency were investigated in detail. And the curcumin release of drug-loaded microspheres was also studied. Results showed that as the emulsifier concentration increased from 0.01% to 0.07%, particle size of the drug-loaded microspheres decreased while particle size distribution, drug loading and entrapment efficiency increased. The optimized concentration of surfactant was 0.05%. With increasing the concentration of drug from 0.03% to 0.07%, drug loading of Cur-HP-β-CD-PiBCA increased, but encapsulation efficiency decreased. Additionally, the results of drug release experiments revealed that the higher drug loading of Cur-HP-β-CD-PiBCA was, the lower cumulative release percentage was. Drug-loading of cumulative inclusions in HP-β-CD by PiBCA can improve its wettability, and increase the degree of dissolution and bioavailability.
Objective To study the release properties of basic fibroblast growth factor (bFGF) chitosan microspheres prepared by cross-linking-emulsion method using chitosan as a carrier material so as to lay a foundation for further study. Methods Using 0.6% sodium tripolyphosphate solution as a crosslinking agent and 1.5% solution of chitosan as a carrier material, bFGF chitosan microspheres were prepared by cross-linking-emulsion method. Laser particle size analyzer and Zeta electric potential analyzer were used to measure the particle diameter distribution, scanning electronic microscope to observe the morphology, and ELISA to determine the drug loading, the encapsulation rate, and the drug release properties. Results The particle size of bFGF chitosan microspheres ranged 20.312-24.152 μm. The microspheres were round with a smooth surface and uniform distribution, and it had no apparent porosity. The drug loading and encapsulation rate of microspheres were (7.57 ± 0.34) mg/g and 95.14% ± 1.58%, respectively. The bFGF chitosan microspheres could continuously release bFGF for 24 days; the bFGF level increased gradually with time and reached (820.45 ± 21.34) ng/mL at 24 days; and the microspheres had a burst effect, and the burst rate was 18.08%, and the accumulative release rate of the microspheres reached 82.05% during 24 days. Conclusion It is easy-to-operate to prepare the bFGF chitosan microspheres with the cross-linking-emulsion method. The bFGF chitosan microspheres have smooth surface, uniform distribution, and no apparent porosity.
Objective To investigate the promotion effects of the collagen membrane incorporating bFGF impregnated microspheres on the wound healing of the pigskin losing its full-thickness layers. Methods The bFGF containing microspheres was added into the dry microspleres.The collagen membranes were prepared by incorporating bFGF-impregnated microspheres, and 6 York pig models of skin wounds with loss of their full-thickness layers were established for the ob servation of the effects on the wound healing. Results The healing time and the 28day healing rate were 27.30±1.14 days and 98.12%±1.97%, respectively.The healing rate was significantly higher and the healing time was significantl y shorter in the experimental group than in the control group (Plt;0.05). The histological examination showed that the proliferation condition of the epidermiswasalso much better in the experimental group. Conclusion Incorporation of bFGF-impregnated microspheres into the collagen membrane is a promising method of pro moting the healing of the wound with a loss of the fullthickness skin.
Calcium phosphate cement (CPC) has been widely used as bone fillers because of its excellent bioactivity and biocompatibility. Meanwhile, CPC is also an attractive candidate for the incorporation of drug or microspheres, because the preparing procedure avoids sintering and heating release. This paper summarizes the clinical applications of microspheres incorporated in CPC from the aspects of sustained drug release, accelerated degradation, porous structure and improved mechanical properties. The paper is aimed to analyze the methods and principles of microspheres loaded CPC, and so as to lay a foundation for the further research of improving and manufacturing the CPC with ideal properties.
Objective To investigate the preparation and properties of the novel silica (SiO2)/hydroxyapatite (HAP) whiskers porous ceramics scaffold. Methods The HAP whiskers were modified by the SiO2 microspheres using the St?ber method. Three types of SiO2/HAP whiskers were fabricated under different factors (for the No.1 samples, the content of tetraethoxysilane, stirring time, calcination temperature, and soaking time were 10 mL, 12 hours, 560℃, and 0.5 hours, respectively; and in the No.2 samples, those were 15 mL, 24 hours, 650℃, and 2 hours, respectively; while those in the No.3 samples were 20 mL, 48 hours, 750℃, and 4 hours, respectively). The phase and morphology of the self-made HAP whisker and 3 types of SiO2/HAP whiskers were detected by the X-ray diffraction analysis and scanning electron microscopy. Taken the self-made HAP whisker and 3 types of SiO2/HAP whiskers as raw materials, various porous ceramic materials were prepared using the mechanical foaming method combined with extrusion molding method, and the low-temperature heat treatment. The pore structure of porous ceramics was observed by scanning electron microscopy. Its porosity and pore size distribution were measured. And further the axial compressive strength was measured, and the biodegradability was detected by simulated body fluid. Cell counting kit 8 method was used to conduct cytotoxicity experiments on the extract of porous ceramics. Results The SiO2 microspheres modified HAP whiskers and its porous ceramic materials were prepared successfully, respectively. In the SiO2/HAP whiskers, the amorphous SiO2 microspheres with a diameter of 200 nm, uniform distribution and good adhesion were attached to the surface of the whiskers, and the number of microspheres was controllable. The apparent porosity of the porous ceramic scaffold was about 78%, and its pore structure was composed of neatly arranged longitudinal through-holes and a large number of micro/nano through-holes. Compared with HAP whisker porous ceramic, the axial compressive strength of the SiO2/HAP whisker porous ceramics could reach 1.0 MPa, which increased the strength by nearly 4 times. Among them, the axial compressive strength of the No.2 SiO2/HAP whisker porous ceramic was the highest. The SiO2 microspheres attached to the surface of the whiskers could provide sites for the deposition of apatite. With the content of SiO2 microspheres increased, the deposition rate of apatite accelerated. The cytotoxicity level of the prepared porous ceramics ranged from 0 to 1, without cytotoxicity. Conclusion SiO2/HAP whisker porous ceramics have good biological activity, high porosity, three-dimensional complex pore structure, good axial compressive strength, and no cytotoxicity, which make it a promising scaffold material for bone tissue engineering.
Objective To evaluate the effect of the local del ivery of basic fibroblast growth factor 2 (bFGF-2) on the osseointegration around titanium implant of diabetic rats. Methods The bFGF-2-loaded poly (lactic-co-glycol ic acid) microspheres were prepared by water/oil/water (W/O/W) double-emulsion solvent evaporation method. Thirty-five male SPF level Sprague Dawley rats, weighing 220-250 g and aged 9 weeks, were selected as experimental animals. Ten rats were fedwith the routine diet as normal control group. The other 25 rats were made the diabetic animal model by giving high fat-sugar diet and a low dose streptozotocin (30 mg/ kg) intravenously; 20 rats were made the diabetic animal model successfully. Then 20 rats were randomly divided into diabetic control group (n=10) and bFGF-2 intervention group (n=10). A hole was drilled in the right tibia bone of all rats, and the titanium implant treated by micro-arc oxidation surface was planted into the hole. Simultaneously, the previously prepared microspheres and blood were mixed and were loaded on the surface of the implant before it was implanted into the rats of the bFGF-2 intervention group. At 4 and 8 weeks, the tibia containing implants was harvested, embedded with resin and made undecalcified tissue sl ices to compare the osseointegration. Results At 4 weeks, the implants of the normal control group were surrounded by new lamellar bone with continuity; whereas the tissue around the implants of the diabetic control group contained l ittle woven bone and some fibrous tissue; and obvious new formed bone with continuity was observed in bFGF-2 intervention group. At 8 weeks, the results of 3 groups were similar to those at 4 weeks. At 4 weeks, the percentage of bone-implant contact (BIC) in diabetic control group was significantly less than those in normal control group (P lt; 0.05) and in bFGF-2 intervention group (P lt; 0.05); the BIC in bFGF-2 intervention group was less than in normal control group, but showing no significant difference (P gt; 0.05). After 8 weeks, the BIC in normal control group and in bFGF-2 intervention group were significantly greater than that in diabetic control group (P lt; 0.05), but there was no significant difference between bFGF-2 intervention group and normal control group (P gt; 0.05). Conclusion Local del ivery of bFGF-2 around titanium implants may improve the osseointegration in diabetic rats.
Objective To investigate the growth of tumors and the natural life length of the rats after the adriamycinethylcellulose microspheres(ADM-EC mc) were injected in the rats bearing transplantable liver cancer through their hepatic arteries.Methods ADM-EC mc were infused into the proper hepatic arteries of the Wistar rats (W256). All of the rats were divided randomly into five groups, group 1: control, group 2: normal saline, group 3: conventional ADM, group 4: placebo ethylcellulose microspheres, and group 5: ADM-EC mc. Results As compared with other four groups, the ADM-EC mc (group 5) showed the best inhibition of the growth of tumors and the longest mean life length of the rats. Conclusion Hepatic arterial infusion of ADM-EC mc can inhibit the growth of the tumor, aggravate the necrosis, and improve the effects of the chemotherapy of liver cancer.
The “Expert consensus on the standardized procedure of selective internal radiation therapy with yttrium-90 microspheres for liver malignancies (2024 edition)” is China’s first comprehensive technical guideline on yttrium-90 microsphere selective internal radiation therapy (90Y-SIRT). It was developed collaboratively by domestic experts in interventional radiology, hepatobiliary surgery, nuclear medicine, and other related fields. This consensus systematically outlines the standardized requirements for the entire process of 90Y-SIRT, including patient selection, preoperative assessment, dosage calculation, procedural technique, and postoperative management. This section provides an in-depth interpretation of the consensus’s core elements, focusing on analyzing its innovations and differences compared to international guidelines and previous domestic practices. It highlights the consensus’s guiding value in promoting the safe, standardized, and efficient implementation of this technology in China, offering a reference for clinical practice to physicians across multiple disciplines such as hepatobiliary surgery, interventional radiology, medical oncology, and nuclear medicine.
Four pigs underwent the hepatic arterial infusion with 32P glass microsphere (32PGM) and pigs were killed in 15th, 30th and 90th days separately. Pathological study showed that in early stage there were many small necrotic areas scattered along the hepatic arterioles. Three months later, these necrosis were gradually absorbed and replaced by regenerating hepatic cells. Tumor-inhibition experiment was performed in 40 Bal B/C mice bearing H22 hepatoma. Intratumoral injection of 0.2ml of 32PGM/glycerine suspension (group A, n=20) or 0.2ml of blank glass microsphere/glycerine suspension (group B, n=20) were performed. The average survival time in group A and group B was 24.8 and 11.8 days respectively. Five mice in group A were alive beyond 40 days after treatment, disappearance of tumor was found in two of them. This experiment demonstrates that 32PGM is effective for treatment of experiment hepatoma. The damage to hepatic tissue after infusion is associated with the irregular distribution of microsphere, and this lesion can completely recover within three months.