Researchers are exploring the use of microneedle technology to deliver treatment for staph skin infections.
Antimicrobial resistance (AMR) is a growing problem worldwide. It is so serious, the World Health Organization named AMR as one of the top ten global public health threats facing humanity (1). Antimicrobials are the class of drugs used to fight infections caused by microbiological pathogens, such as bacteria, viruses, fungus, and parasites.
Antimicrobial resistance occurs when the bacteria, viruses, fungi, and parasites either mutate to develop resistance to the drug or transfer genetic material with resistant cells to acquire immunity to the drugs (2).
When microbials become resistant to antimicrobial treatment, healthcare providers are no longer able to easily treat common infections such as pneumonia, tuberculosis, blood poisoning, gonorrhea, and foodborne diseases (1). This increases healthcare costs and the danger of infections.
Microbials that develop resistance have been nicknamed “superbugs” because the normal antimicrobial drugs are no longer able to treat the infections. Antimicrobial resistance has been caused in part by the over prescription of common antimicrobial drugs and overuse of these drugs by the public.
Some of the antimicrobial resistance threats are carbapenem-resistant Acinetobacter and Enterobacterales, drug-resistant Campylobacter, Candida, Salmonella, Streptococcus pneumoniae, and Methicillin-resistant Staphylococcus aureus (MRSA) (3).
Staphylococcus aureus is a prevalent bacterium that is colonized on 30% of peoples’ skin. It is also the main cause of many common infections (4). Beginning in the 1930s, penicillin was used to treat staph infections (4). However, within two years, Staphylococcus aureus had developed resistance to penicillin, and doctors began to treat these infections with the antibiotic methicillin (6) (7).
Unfortunately, Staphylococcus aureus also developed resistance to methicillin, leading to difficult to treat skin and soft tissue infections (8) known as methicillin-resistant Staphylococcus aureus (MRSA). There are two primary types of MRSA – hospital acquired MRSA (HA-MRSA) and community associated MRSA (CA-MRSA).
Skin and soft tissue infections account for 7-10% of annual hospitalizations (9) (7) and are increasingly difficult to treat because of MRSA. One promising antibiotic used to treat MRSA is vancomycin hydrochloride (VAN). However, VAN does not absorb well when taken orally, nor does it work well when applied to the skin due to its molecular size. When administered intravenously, VAN can cause debilitating side effects such as pain, kidney damage, or even anaphylaxis (7).
These challenges prompted researchers at the Karolinska Institutet in Sweden to develop a unique way to deliver VAN directly to the MRSA skin infection. They have developed polymeric microneedles (MNs) loaded with vancomycin. The microneedle patches are applied directly over the MRSA skin infection to deliver the antibiotic treatment.
The research team conducted a study of microneedle technology. The study included the fabrication of the microneedles from polymers loaded with VAN. It also investigated the MNs ability to penetrate by testing the needles on a waxy, flexible plastic film, pig skin, and human skin. In their experiments, the MNs were able to penetrate to adequate levels to deliver the medicine painlessly (7).
The microneedles were able to deliver adequate amounts of vancomycin within 10 minutes, delivering 500 times more VAN to the infection than those patients who were treated with VAN intravenously (7). The study tested MN delivery of VAN to MRSA infections colonized on agar plates in the laboratory. VAN delivered by MNs was able to successfully treat MRSA infections and lost none of its antibacterial activity. Investigators also treated MRSA infected pig skin with VAN delivered by MNs, and the MRSA infections were significantly reduced.
In a press release study author Georgios Sotiriou, principal researcher at the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet stated, “If this drug delivery device reaches the clinics, it has the capacity to transform the way skin infections from potentially lethal bacteria are treated with drastic improvements in the quality of life of patients.”
The study authors are hopeful the microneedle technology can be further developed and used as an effective treatment for MRSA. In the future, the research team plans to evaluate the MNs in animals with MRSA and improve its efficacy.
1. World Health Organization. Antimicrobial resistance. World Health Organization. [Online] October 13, 2020. [Cited: May 13, 2021.] https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance.
2. The George Washington University Milken Institute School of Public Health. How Bacteria Build Resistance at the Cellular Level. Milken Institute School of Public Health. [Online] August 28, 2017. [Cited: May 13, 2021.] https://onlinepublichealth.gwu.edu/resources/antibiotic-resistance-at-cellular-level/.
3. Centers for Disease Control and Prevention. Biggest Threats & Data. Antiobiotic / Antimicrobial Resistance (AR / AMR). [Online] 2019. [Cited: May 13, 2021.]
4. Staphylococcus aureus Infections: Epidemiology, Pathophysiology, Clinical Manifestations, and Management. Tong, Steven Y. C., et al. 3, s.l. : online, 2015, Vol. 28.
5. Centeres for Disease Control and Prevention. The Discovery of Penicillin – New Insights After More Than 75 Years of Clinical Use. Centers for Disease Control and Prevention. [Online] May 2017. [Cited: May 13, 2021.] https://onlinepublichealth.gwu.edu/resources/antibiotic-resistance-at-cellular-level/.
6. The evolutionary history of methicillin-resistant Staphylococcus aureus (MRSA). Enright, Mark C., et al. 11, May 28, 2002, Proceedings of the National Academy of Sciences of the United States of America, Vol. 99, pp. 7687-7692.
7. Methicillin-Resistant Staphylococcus aureus: Molecular Characterization, Evolution, and Epidemiology. Lakhundi, Sahreena and Zhang, Kunyan. 4, Sept. 12, 2018, Vol. 31.
8. drugs.com. Antiobiotic Resistance: The Top 10 List. Drugs.com. [Online] July 29, 2019. [Cited: May 13, 2021.] https://www.drugs.com/article/antibiotic-resistance.html.
9. Vancomycin‐Loaded Microneedle Arrays against Methicillin‐Resistant Staphylococcus Aureus Skin Infections. Ziesmer, Jill, et al. May 5, 2021.
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