# Single-dose oral administration of drug-loaded magnetic 3D-printed microbullets for eradication of Helicobacter pylori

## TL;DR

A new drug-loaded microbullet was developed to target and eradicate Helicobacter pylori in the stomach with a single dose, avoiding traditional antibiotic side effects.

## Contribution

The development of a 3D-printed magnetic microbullet for targeted, long-term drug release against H. pylori.

## Key findings

- The microbullet successfully targeted the pylorus and released clarithromycin for over 24 hours.
- Single-dose administration of the microbullet eradicated H. pylori in infected mice.
- The microbullet was confirmed safe in vitro and in vivo with complete evacuation after use.

## Abstract

Infections of Helicobacter pylori (H. pylori) affect 42.1 % of the Chinese population and 43.1 % of the world population. H. pylori inhabits the mucous sublayer at the pylorus, leading to gastric ulcers, gastritis, and even cancer. Oral antibiotics are usually used to treat H. pylori infections, whereas traditional quadruple therapy has side effects including headaches, nausea, diarrhea, intestinal dysbacteriosis, antibiotic resistance, and repeat infections. Here, a drug-loaded magnetic microbullet was designed to realize long-term retention in the stomach for one-shot treatment for H. pylori infections. It comprises a hollow cylinder wherein eight microneedles homogenously distribute at the top and several round pores located at the bottom. It was three-dimensional (3D)-printed by stereolithography. A clarithromycin (CAM) ground mixture (CGM) was prepared to improve solubility. Enough CGM powders were filled into the cylinder, covered by a small round magnet, and sealed to form a CAM-loaded magnetic microbullet (CMMB). CAM continually released from CMMBs for >24 h. With outside magnetic guidance, an oral CMMB targeted the pylorus site and the microneedles immediately headed into the mucosa followed by long-term local drug release. The in vitro and in vivo safety of CMMBs was confirmed, where their swelling rates were low, and the oral CMMB was finally completely evacuated. An oral CMMB was administered to H. pylori-infected mice and maintained in the stomach for 36 h with magnetic guidance, and the successful eradication of H. pylori was confirmed after single-dose administration. Oral CMMBs are a convenient medication for the eradication of H. pylori.

Image, graphical abstract