Effect of Hyaluronic Acid and Pluronic-F68 on the Surface Properties of Foam as a Delivery System for Polidocanol in Sclerotherapy

Efficacy and safety of hyaluronic-polidocanol foam in sclerotherapy for head and neck venous malformations

Background

Foam sclerotherapy is currently the first-line treatment for venous malformations (VMs). Hyaluronic acid-polidocanol (HA-POL) foam has been used in the treatment of head and neck VMs recently; however, its clinical efficacy and safety have yet to be further evaluated, and the impact of age and other related factors on its safety is still unclear.

Objective

To assess the efficacy and safety of HA-POL foam in the treatment of head and neck VMs.

Methods and materials

We performed a single-center retrospective review of all patients with VMs involving the head and neck region undergoing HA-POL foam sclerotherapy from February 2015 to February 2022 in the Oral and Maxillofacial Surgery Department of Qilu Hospital Shandong University. Patients' medical records were collected and all patients enrolled were followed up for 1-6 months (group 1), part of them were followed up for 3-9 years (group 2).

Results

A total of 223 patients with head and neck VMs were enrolled in the study, with 36 patients who were followed for 3-9 years. Total response rate in group 1 was 96.41% (n = 215), of which 30.94% (n = 69) of the patients met the criteria of "resolution," and 65.47% (n = 146) of the patients had "significant improvement." In group 2, the total response rate was 72.22% (n = 26), of which the rates of the patients met the criteria of "resolution" and patients had "significant improvement" were all 36.11% (n = 13)0.144 (64.57%) patients experienced complications like localized swelling, pain and fever, and no serious complications occurred. The risk of developing complications after treatment was independent of age, and was weakly associated with the dose of HA-POL foam.

Conclusion

The HA-POL foam sclerotherapy is safe and effective in the treatment of head and neck VMs.

First In Vivo Applicational Data of Foam-Based Intrathoracic Chemotherapy (FBiTC) in a Swine Model

BACKGROUND

For decades, both intraperitoneal and pleural chemotherapy (IPC) have been delivered as a liquid solution. Recent studies suggest that foam carriers outperform liquid carriers for locoregional chemotherapy. For the first time, this study aims to evaluate the feasibility, safety, and characteristics of foam-based intrathoracic chemotherapy (FBiTC) in an in vivo setting.

METHODS

In this study, contrast-enhanced FBiTC with doxorubicin was delivered via video-assisted thoracoscopy (VAT) in three swine under general anesthesia. Intraoperative and postoperative parameters, blood analyses, vital signs, and anesthesiologic data were collected. Additionally, an intraoperative computer tomography (CT) scan was performed, and histological tissue sections were collected and further analyzed using fluorescence microscopy.

RESULTS

FBiTC was delivered without major complications. End-tidal capnometry detected increased CO2 levels with reduced peripheral oxygen saturation and increased blood pressure and heart rate. No major intra- or postoperative complications were observed. CT scans confirmed a multidirectional distribution pattern of foam. Postoperative laboratory workup did not reveal any critical changes in hemoglobin, white blood count, or platelets. There was no evidence of critical kidney impairment or liver function. Fluorescence microscopy of tissue specimen detected doxorubicin in pleural tissues.

DISCUSSION

Our preliminary results are encouraging and indicate that FBiTC is feasible. However, to consider a possible clinical application, further studies are required to investigate the pharmacologic, pharmacodynamic, and physical properties of FBiTC and to ensure the safety of the overall procedure regarding oxygenation levels and capnography parameters.

The role of hyaluronic acid in polidocanol foam: An in vitro study

Objective

To study the role of hyaluronic acid (HA) in polidocanol (POL) foam.

Methods

The dose-dependent effect of HA-POL on cultured human umbilical vein endothelial cells (HUVECs) as well as foam stability was evaluated by measuring optical density (OD) values and foam half-life time (FHT), respectively. An in vitro model was utilized for estimating the foam blood-displacement capacity by adopting maximum displacement distance (MDD) and displacement time. A comparison of foam viscosity was also carried out.

Results

The OD values of HUVECs treated with HA first increased and then decreased with the growing dosage of HA while cells treated with HA-POL died. Both FHT and displacement time were prolonged statistically with a gradually enhanced foam viscosity. As to MDD, there were no significant differences.

Conclusions

HA was found to promote HUVECs proliferation slightly, but this was almost negligible when compared to the cell-killing capacity of 1% POL. The viscosity of POL foam was enhanced by HA indicating its positive correlation with both stability and displacement capacity of POL foam.

Biopredictive tools for the development of injectable drug products

INTRODUCTION

Biopredictive release tests are commonly used in the evaluation of oral medicines. They support decision-making in formulation development and allow predictions of the expected in-vivo performances. So far, there is limited experience in the application of these methodologies to injectable drug products.

AREAS COVERED

Parenteral drug products cover a variety of dosage forms and administration sites including subcutaneous, intramuscular, and intravenous injections. In this area, developing biopredictive and biorelevant methodologies often confronts us with unique challenges and knowledge gaps. Here, we provide a formulation-centric approach and explain the key considerations and workflow when designing biopredictive assays. Also, we outline the key role of computational methods in achieving clinical relevance and put all considerations into context using liposomal nanomedicines as an example.

EXPERT OPINION

Biopredictive tools are the need of the hour to exploit the tremendous opportunities of injectable drug products. A growing number of biopharmaceuticals such as peptides, proteins, and nucleic acids require different strategies and a better understanding of the influences on drug absorption. Here, our design strategy must maintain the balance of robustness and complexity required for effective formulation development.

A Novel Drug Self-Delivery System from Fatty Alcohol Esters of Tranexamic Acid for Venous Malformation Sclerotherapy

Venous malformation (VM), which causes severe damage to patients' appearance and organ function, is one of the most common vascular malformations. At present, many drugs in clinical treatment cause various adverse reactions. Herein, we synthesized cationic amphiphilic gelators (TA6, TA8, and TA9) by introducing saturated carbon chains of different lengths to tranexamic acid (TA), which could self-assemble into low-molecular-weight gels (LMWGs) as drug delivery carriers by hydrogen bonds, van der Waals forces, and hydrophobic interactions. The rheological properties, gelation driving force and drug release profiles of TA6, TA8, and TA9 hydrogels were characterized, and the results indicated that the hydrogels prepared in this study possessed the typical characteristics of a gel and could release drugs slowly. More importantly, the TA9 gelator showed significant pharmacological activity, in that it served as both an active drug compound and a drug carrier. The in vitro experiments demonstrated that TA9 induced HUVECs death and hemolysis by destroying cell membranes in a dose-dependent manner, and caused cell death and hemolysis at a concentration of 0.09 µM/mL. Meanwhile, we found TA9 could interact not only with fibrinogen, but also with other endogenous molecules in the blood. After the administration of TA9 hydrogel for 15 days, macroscopic imaging and histological evaluation in mice and rabbits displayed obvious thrombi, inflammatory reactions, and venous embolization, indicating that the mechanism of the TA9 hydrogel in treating VM was involved in two processes. Firstly, the TA9 hydrogel relied on its mechanical strength to physically block veins and continuously release TA9, in situ, for targeted therapy. Then, TA9 destroyed endothelial cells and damaged venous walls critically, causing thrombi. Most excitingly, TA9 was hydrolyzed to TA by enzymes that inhibited the degradation of thrombi by plasmin to prolong the embolization time and to promote venous fibrosis. Compared with other clinically available sclerosants, the degradation of TA9 also empowered a better biocompatibility and biodegradability for the TA9 hydrogel. In conclusion, we synthesized a potentially safe and effective derivative of TA and developed a low-molecular-weight gel as a self-delivery system for TA in treating VM.