Cisplatin-conjugated degradable gelatin microspheres: fundamental study in vitro

Antiviral Activities of Andrographolide and Its Derivatives: Mechanism of Action and Delivery System

Andrographispaniculata (Burm.f.) Nees has been used as a traditional medicine in Asian countries, especially China, India, Vietnam, Malaysia, and Indonesia. This herbaceous plant extract contains active compounds with multiple biological activities against various diseases, including the flu, colds, fever, diabetes, hypertension, and cancer. Several isolated compounds from A. paniculata, such as andrographolide and its analogs, have attracted much interest for their potential treatment against several virus infections, including SARS-CoV-2. The mechanisms of action in inhibiting viral infections can be categorized into several types, including regulating the viral entry stage, gene replication, and the formation of mature functional proteins. The efficacy of andrographolide as an antiviral candidate was further investigated since the phytoconstituents of A. paniculata exhibit various physicochemical characteristics, including low solubility and low bioavailability. A discussion on the delivery systems of these active compounds could accelerate their development for commercial applications as antiviral drugs. This study critically reviewed the current antiviral development based on andrographolide and its derivative compounds, especially on their mechanism of action as antiviral drugs and drug delivery systems.

Progress of gelatin-based microspheres (GMSs) as delivery vehicles of drug and cell

Gelatin has various attractive features as biomedical materials, for instance, biocompatibility, low immunogenicity, biodegradability, and ease of manipulation. In recent years, various gelatin-based microspheres (GMSs) have been fabricated with innovative technologies to serve as sustained delivery vehicles of drugs and genetic materials as well as beneficial bacteria. Moreover, GMSs have exhibited promising potentials to act as both cell carriers and 3D scaffold components in tissue engineering and regenerative medicine, which not only exhibit excellent injectability but also could be integrated into a macroscale construct with the laden cells. Herein, we aim to thoroughly summarize the recent progress in the preparations and biomedical applications of GMSs and then to point out the research direction in future. First, various methods for the fabrication of GMSs will be described. Second, the recent use of GMSs in tumor embolization and in the delivery of cells, drugs, and genetic material as well as bacteria will be presented. Finally, several key factors that may enhance the improvement of GMSs were suggested as delivery vehicles.

Drug-eluting embolic microspheres for local drug delivery - State of the art

Embolic microspheres or beads used in transarterial chemoembolization are an established treatment method for hepatocellular carcinoma patients. The occlusion of the tumor-feeding vessels by intra-arterial injection of the beads results in tumor necrosis and shrinkage. In this short review, we describe the utility of using these beads as devices for local drug delivery. We review the latest advances in the development of non-biodegradable and biodegradable drug-eluting beads for transarterial chemoembolization. Their capability to load different drugs, such as chemotherapeutics and anti-angiogenic compounds with different physicochemical properties, like charge and hydrophilicity/hydrophobicity, are discussed. We specifically address controlled and sustained drug release from the microspheres, and the resulting in vivo pharmacokinetics in the plasma vs. drug distribution in the targeted tissue.

Preparation of gelatin nanospheres incorporating quantum dots and iron oxide nanoparticles for multimodal cell imaging

The objective of this study is to prepare a multimodal probe which can simultaneously visualize cells by optical and magnetic resonance (MR) imaging modalities. Gelatin nanospheres incorporating quantum dots (QD) and iron oxide nanoparticles (IONP) were prepared by the conventional emulsion method. The percentage of QD and IONP incorporated in gelatin nanospheres was changed by the concentrations of gelatin and glutaraldehyde used. However, the apparent size and surface zeta potential were hardly changed. Gelatin nanospheres incorporating QD and IONP were treated with octa-arginine (R8) of a cell-penetrating peptide. When incubated with normal human articular chondrocytes, gelatin nanospheres incorporating QD and IONP were efficiently internalized into the cells although their cytotoxicity was observed at the R8 concentration of 320 μM. The cells internalizing gelatin nanospheres incorporating QD and IONP could be visualized by both the optical and MR imaging modalities. It is concluded that gelatin nanospheres incorporating QD and IONP are promising for the probe of multimodal cell imaging.

Evaluation of the role of cisplatin-conjugated-soluble gelatin sponge: feasibility study in a swine model

PURPOSE

To evaluate the safety and the delivery function of cisplatin-conjugated-soluble gelatin sponge in a swine model.

METHODS

Fifteen healthy young swine were assigned into three groups: transarterial cisplatin infusion group, transarterial chemoembolization (TACE) with cisplatin-conjugated 120-min soluble gelatin sponge (TACE-120) group, and TACE with cisplatin-conjugated 360-min soluble gelatin sponge (TACE-360) group. A total volume of 0.8 mL/kg cisplatin in each group and 8 mg/kg soluble gelatin sponge in TACE-120 and TACE-360 groups were injected from the left hepatic artery in small increments for 10 min. Common hepatic angiography and whole-blood sampling via the left hepatic vein were conducted to explore recanalization immediately after the procedure and again at 10, 30, 60, 90, 120, 180, 240, 300, 360, and 420 min later. The area under the plasma concentration curve (AUC) of non-protein-bound platinum was compared among the three groups. Each liver was removed and cut into 10-cm-thick sections for calculating liver-damaged volume ratio.

RESULTS

Sequential angiography depicted gradual recanalization of the occluded hepatic artery and total recanalization at 120 and 360 min after embolization in the TACE-120 and TACE-360 groups, respectively. Of the three groups, AUC(0-30), AUC(30-120), and AUC(120-420) were significantly highest in the transarterial cisplatin infusion group (p < 0.001), the TACE-120 group (p < 0.001), and the TACE-360 group (p < 0.001), respectively. The liver-damaged volume ratio in the TACE-360 group was small (8.20 %) but significantly higher than that in the TACE-120 group (2.67%, p = 0.014).

CONCLUSION

Cisplatin-conjugated soluble gelatin sponge functions as a cisplatin carrier and is associated with tolerable liver damage.

Clinical trial of cisplatin-conjugated gelatin microspheres for patients with hepatocellular carcinoma

PURPOSE

We report our initial experience with the transarterial chemoembolization (TACE) of unresectable hepatocellular carcinoma (HCC) using cisplatin-conjugated gelatin microspheres (Cis-GMS).

METHODS AND MATERIAL

Nineteen patients with 25 HCC nodules (mean diameter 23.0 mm) were treated by selective TACE using 50- to 100-μm Cis-GMS. Tumor necrosis and postembolization syndrome were assessed during the follow-up. The tumor response was evaluated on contrast-enhanced computed tomography images at 1 and 3 months after TACE using Cis-GMS.

RESULTS

All procedures were technically successful in all patients; following the TACE using Cis-GMS, there were no major complications, and postembolization syndrome was minimal. At the 1-month follow-up, the response rate was 12 of the 25 (48%) and 21 of the 25 (84%) HCC nodules based on RECIST 1.1 and EASL criteria, respectively; at the 3-month follow-up, it was 10 of the 25 (40%) and 14 of the 25 (56%) HCC nodules, respectively.

CONCLUSION

Our initial experience with using Cis-GMS for TACE suggests that these drugs may represent an optimal treatment option for the treatment of advanced HCC and that the use of gelatin microspheres loaded with chemotherapeutic agents warrants further study.

Enhanced antitumor effect of tirapazamine delivered intraperitoneally to VX2 liver tumor-bearing rabbits subjected to transarterial hepatic embolization

PURPOSE

We evaluated the effects of the combination of Tirapazamine (TPZ), activated preferentially under hypoxic conditions, and gelatin microspheres (GMS) on the tumor growth ratio in rabbits.

METHODS

We assigned 20 liver tumor-bearing Japanese white rabbits to 4 equal groups. Group 1 received 1 ml of saline intra-arterially (i.a.) and 20 ml of saline intraperitoneally (i.p.; saline group). Group 2 was injected with GMS i.a. and 20 ml saline i.p. (GMS group). Group 3 received 1 ml of saline i.a. and 300 mg/m(2) of TPZ i.p. (TPZ group), and group 4 was treated with GMS i.a. and 300 mg/m(2) of TPZ i.p. (GMS + TPZ group). The infusion of GMS was stopped when the blood flow stagnated. Before and 7 days after treatment, the liver tumor volumes were measured as the total number of pixels on 0.3Tesla (T) magnetic resonance imaging (MRI) scans.

RESULTS

The tumor growth ratio (mean ± standard deviation) of the saline, GMS, TPZ, and GMS + TPZ groups was 519.15 ± 93.78, 279.24 ± 91.83, 369.78 ± 95.73, and 119.87 ± 17.62, respectively. The difference between the GMS + TPZ group and the other groups was statistically significant (P < 0.05).

CONCLUSIONS

Our results show that the combination of TPZ i.p. and GMS i.a. enhanced the antitumor effect of TPZ. This procedure may represent a new alternative treatment for patients with hepatic cell carcinoma.

Cisplatin-conjugated porous gelatin particles: assessment of optimal conditions for binding and release

This study was designed to evaluate the optimal conditions for binding cisplatin and porous gelatin particles (PGPs) and to establish in vivo drug release pharmacokinetics. PGPs were immersed in cisplatin solutions under different conditions: concentration, immersion time, and temperature. Thereafter, PGPs were washed in distilled water to remove uncombined cisplatin and were then freeze-dried. The platinum concentration (PC) in the PGPs was then measured. For the in vivo release test, 50 mg/kg of the cisplatin-conjugated PGPs was implanted subcutaneously in the abdominal region of two rabbits. PCs in the blood were measured at different time intervals. PCs significantly increased in direct proportion to the concentration and immersion time (p < 0.01). Although PC increased at higher solution temperature, it was not a linear progression. For the in vivo release test, platinum was released from cisplatin-conjugated PGPs after 1 day, and the peak PC was confirmed 2 days after implantation. Platinum in the blood was detected until 7 days after implantation in one rabbit and 15 days after administration in the other rabbit. Platinum binding with PGPs increased with a higher concentration of cisplatin solution at a higher temperature over a longer duration of time. Release of cisplatin from cisplatin-conjugated PGPs was confirmed in vivo.

A combination of cisplatin-eluting gelatin microspheres and flavopiridol enhances anti-tumour effects in a rabbit VX2 liver tumour model

The aim of this study was to investigate whether the combination of cisplatin-eluting gelatin microspheres (GMSs) and flavopiridol enhances anti-tumour effects in a rabbit VX2 liver tumour model. Tumour-bearing rabbits (n = 21) were divided into five groups and infused from the proper hepatic artery. Group 1 (n = 5) received cisplatin-eluting GMSs (1 mg kg(-1)) and flavopiridol (3 mg kg(-1)), group 2 (n = 5) cisplatin-eluting GMSs alone (1 mg kg(-1)), Group 3 (n = 5) flavopiridol (3 mg kg(-1)), Group 4 (n = 3) GMSs alone (1 mg kg(-1)), and Group 5 (n = 3) was the control group receiving physiological saline (1 ml kg(-1)). On days 0 and 7 after procedures the liver tumour volume was measured using a horizontal open MRI system and the relative tumour volume growth rates for 7 days after treatment were calculated. On T(1) weighted images, the tumours were visualised as circular, low-intensity areas just below the liver surface. After treatment, the signals remained similar. The relative tumour volume growth rate for 7 days after treatment was 54.2+/-22.4% in Group 1, 134.1+/-40.1% in Group 2,166.7+/-48.1% in Group 3, 341.8+/-8.6% in Group 4 and 583.1+/-46.9% in Group 5; the growth rate was significantly lower in Group 1 than the other groups (p<0.05). We concluded that in our rabbit model of liver tumours the combination of cisplatin-eluting GMSs and flavopiridol was effective.