The short-term safety and efficacy of TANDEM microspheres of various sizes and doxorubicin loading concentrations for hepatocellular carcinoma treatment

Drug-eluting bead transarterial chemoembolization (DEB-TACE) is the most common treatment for unresectable hepatocellular carcinoma (HCC). However, the effect of drug loading concentration and microsphere size on treatment outcomes remains unclear. This retrospective study compares the outcomes of 87 HCC patients who underwent DEB-TACE with half-loaded or full-loaded doxorubicin (maximum capacity 50 mg/mL) in 75-µm or 100-µm microspheres. Treatment with 100-μm microspheres resulted in significantly lower rates of procedure-related complications (6.6% vs. 26.9%; P < 0.05), post-embolization syndrome (32.8% vs. 61.5%, P < 0.05), SIR complications (32.8% vs. 61.5%; P < 0.01) and adverse events involving abdominal pain (19.7% vs. 42.3%; P < 0.05). Half-load doxorubicin microspheres resulted in greater treatment response (OR, 4.00; 95% CI 1.06–15.13; P, 0.041) and shorter hospital stays (OR, − 1.72; 95% CI − 2.77–0.68; P, 0.001) than did microspheres loaded to full capacity. Stratified analysis further showed that patients treated with 100-μm half-load doxorubicin microspheres had a higher CR (63.6% vs 18.0%) and ORR (90.9 vs 54.0%) and a shorter hospital stay (1.6 ± 1.3 vs 4.2 ± 2.3 days) than did those treated with full-load microspheres (P < 0.05). Thus, the drug-loading concentration of microspheres in DEB-TACE should be carefully considered.

Determining Trap Compliances, Microsphere Size Variations, and Response Linearities in Single DNA Molecule Elasticity Measurements with Optical Tweezers

We previously introduced the use of DNA molecules for calibration of biophysical force and displacement measurements with optical tweezers. Force and length scale factors can be determined from measurements of DNA stretching. Trap compliance can be determined by fitting the data to a nonlinear DNA elasticity model, however, noise/drift/offsets in the measurement can affect the reliability of this determination. Here we demonstrate a more robust method that uses a linear approximation for DNA elasticity applied to high force range (25–45 pN) data. We show that this method can be used to assess how small variations in microsphere sizes affect DNA length measurements and demonstrate methods for correcting for these errors. We further show that these measurements can be used to check assumed linearities of system responses. Finally, we demonstrate methods combining microsphere imaging and DNA stretching to check the compliance and positioning of individual traps.

Preparation and Swelling Behaviors of High-Strength Hemicellulose-g-Polydopamine Composite Hydrogels

Hemicellulose-based composite hydrogels were successfully prepared by adding polydopamine (PDA) microspheres as reinforcing agents. The effects of PDA microsphere size, dosage, and nitrogen content in hydrogel on the mechanical and rheological properties was studied. The compressive strength of hydrogel was increased from 0.11 to 0.30 MPa. The storage modulus G’ was increased from 7.9 to 22.0 KPa. The gaps in the hemicellulose network are filled with PDA microspheres. There is also chemical cross-linking between them. These gaps increased the density of the hydrogel network structure. It also has good water retention and pH sensitivity. The maximum cumulative release rate of methylene blue was 62.82%. The results showed that the release behavior of hydrogel was pH-responsive, which was beneficial to realizing targeted and controlling drug release.

Development of Theophylline Microbeads Using PregelatinizedBreadfruit Starch (Artocarpus altilis) as a Novel Co-polymer for Controlled Release

Purpose: The aim of this study was to prepare formulations of theophylline microbeads usingpregelatinized breadfruit starch (Artocarpus altilis, family Moraceae) in combination withsodium alginate and chitosan at various polymer: drug ratios. Microbead formulations forcontrolled delivery of theophylline would be better alternatives to conventional dosage formsfor optimized drug therapy.Methods: The native and pregelatinized starches were characterized for morphology (scanningelectron microscope), crystallinity (Fourier transform intra-red spectroscopy, FTIR and X-raydiffractometer, XRD), thermal flow (differential scanning colorimeter), density and flowproperties. Theophylline microbeads were prepared by ionic gelation and characterized usingsize, swelling index, entrapment efficiency and time required for 15% and 50% drug release (t15and t50 respectively).Results: FTIR and XRD spectra revealed the orderly arrangement of granules of the semi-crystallinebreadfruit starch was disrupted on gelatinization. The viscosity and flow of pregelatinized starchwere enhanced. Theophylline microbeads were near spherical in shape with size range 1.09± 0.672 to 1.58 ± 0.54 mm. FTIR and XRD spectra confirmed there was no drug-polymerinteraction. Microsphere size, swelling increased while entrapment and dissolution time (t50)reduced with polymer: drug ratio. The entrapment efficiency ranged from 30.99 ± 1.32 to 78.50± 2.37%. Optimized formulation, starch: alginate ratio 3:1 at polymer: drug ratio of 2:1, gave aprolonged dissolution time (t50 = 8.40 ± 1.20 h).Conclusion: Breadfruit starch was suitable as a copolymer for the controlled delivery oftheophylline in microbeads which could serve as a substitute to synthetic polymers in drugdelivery.

Effects of Microsphere Size on the Mechanical Properties of Photonic Crystals

Photonic crystal (PC) thin films that are self-assembled from different-sized silica microspheres were prepared for studying mechanical properties via nanoindentation at the submicron scale. We found that the silica photonic crystals (PCs) possessed a face-centered cubic (FCC) microstructure and their elastic modulus and hardness were in the range of ~1.81–4.92 GPa and 0.008–0.033 GPa, respectively. The calculated results proved that there were size-dependent properties in the silica PCs, in that the elastic modulus and hardness increased as the diameter decreased from 538 nm to 326 nm. After studying the total work and plastic work in the progressive deformation of silica PCs during the nanoindentation tests, we developed a two-stage deformation model to explain how the microsphere size affects the mechanical properties of PC thin films. The phenomenon of “smaller is stronger” is mainly due to the energy consumption, which combines the effects of microstructure collapse, microsphere slide, and reduced porosity during the whole loading and unloading process. In addition, the results of numerical simulation matched the experimental data and reflected the energy change rules of PCs during the indentation process. Furthermore, the study affords useful guidance for constructing high-performance films with proper design and potential application in next-generation PC materials.

Inexpensive Apparatus for Fabricating Microspheres for 5-Fluorouracil Controlled Release Systems

The aim of this study was to develop an inexpensive apparatus for fabricating microspheres, based on chitosan, for 5-fluorouracil (5-FU) controlled release. Chitosan microspheres were prepared by precipitation method and the effects of manufacturing parameters (injection and airflow rates) on size distribution microspheres were analyzed by optical and scanning electron microscopy. The results show that the manufacturing parameters, injection and airflow rates, determine the microsphere size distribution. By modulating these parameters, it was possible to produce chitosan microspheres as small as 437 ± 44 μm and as large as 993 ± 18 μm. Chitosan microspheres loaded with 5-FU were also produced using the experimental equipment. The obtained microspheres presented 5-FU controlled release, indicating that the microspheres can be used orally, since they are capable of crossing the stomach barrier and of continuing with the process of 5-FU release.