Breakthrough in Diabetes Care: Scientists Develop Needle-Free Insulin Gel

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Breakthrough in Diabetes Care: Scientists Develop Needle-Free Insulin Gel

A groundbreaking development in diabetes treatment is on the horizon, as scientists have successfully engineered a novel polymer-based gel designed to deliver insulin through the skin without the need for injections. This innovative transdermal approach, detailed in a recent study published in the prestigious journal Nature, offers a compelling vision for a future where millions of diabetes patients could manage their blood sugar levels without daily needle pricks.

For individuals living with diabetes, the routine of managing blood sugar often involves multiple daily insulin injections, a process that can be both physically and psychologically demanding. The new polymer gel, named OP, represents a significant leap forward, demonstrating its ability to normalize blood glucose in diabetic mice and pigs within one to two hours of application, maintaining stable levels for approximately 12 hours. This sustained effect is comparable to that of basal insulin shots, which provide a steady dose to stabilize blood sugar between meals and overnight, typically complemented by fast-acting insulin for mealtime spikes.

The ingenuity of this gel lies in its "mechanistically elegant" design, as described by Suchetan Pal, an associate professor and head of the Biomaterials Laboratory at the Indian Institute of Technology Bhilai, who was not involved in the research. The primary hurdle for transdermal delivery of large protein molecules like insulin is the skin's formidable outer layer, the stratum corneum. This layer, though only 10 to 15 micrometers thick, acts as a highly effective barrier against external substances.

The research team, led by Youqing Shen, a professor in the School of Chemical and Biological Engineering at Zhejiang University in China, overcame this challenge by developing a pH-responsive polymer. Human skin's surface is naturally acidic, with a pH of around 5, while deeper layers are closer to a neutral pH of 7. The OP polymer is engineered to become positively charged at the skin's acidic surface, allowing it to adhere to fatty acids within the stratum corneum. As the gel penetrates deeper into the skin where the pH gradually increases, the OP polymer transitions to a neutral state. This critical change enables it to diffuse through the lipid-rich layers of the skin, carrying the chemically linked insulin along with it – a feat insulin alone cannot achieve.

Laboratory tests using excised mouse and pig skin confirmed the OP polymer's ability to penetrate all dermal layers, unlike insulin which remained superficial. Subsequent in-vivo tests on diabetic animals yielded promising results. In a mouse model of diabetes, a single application of the OP-insulin gel brought blood glucose levels to a normal range within an hour, sustained for about 12 hours. However, Pal noted that this required a substantial dose of 116 units per kilogram of body weight (U/kg), significantly higher than typical human insulin doses, raising questions about efficiency for human application.

Crucially, the researchers achieved more efficient delivery in diabetic miniature pigs, whose skin closely mimics human skin. A single dose of approximately 7.25 U/kg successfully restored the pigs' blood glucose to normal levels. Furthermore, repeated applications of the gel on pigs showed no signs of skin irritation or inflammation, a vital safety indicator for future human use.

Should these encouraging animal results translate effectively to humans, the implications are profound. A needle-free insulin gel could significantly benefit patients with needle phobia or aversion, thereby improving adherence to treatment regimens and alleviating the daily burden of diabetes management. The 12-hour duration of effect suggests its potential as a long-acting insulin for background blood sugar control, though fast-acting insulin would still be necessary for mealtime glucose spikes. It's important to note, as Pal highlighted, that the gel's slower, steadier absorption means it cannot rapidly counteract dangerously high blood sugar in emergency situations, a role still reserved for injectable insulin.

Despite the excitement, experts caution that considerable hurdles remain before the gel can be approved for human use. "The polymer hasn't shown any side effects in mice or pigs," stated lead author Youqing Shen, "But humans have used insulin for decades, so we need to investigate long-term toxicity." Controlling the precise insulin dose delivered transdermally is also critical, as excessive amounts could lead to hypoglycemia, a dangerously low blood sugar condition. The path to clinical application involves extensive preclinical safety studies, an Investigational New Drug (IND) filing with regulatory bodies like the FDA, and rigorous human clinical trials.

While the pig studies offered a more relevant model for human skin, Pal underscored the need for further development to optimize efficacy at safe and clinically appropriate human doses. The long-term safety of chronic, repeated gel application also requires thorough investigation. Looking ahead, the research team must refine the optimal formulation and dosing, devise scalable manufacturing processes, and ultimately conduct human clinical trials. Nonetheless, the prospect of needle-free diabetes care through this innovative gel remains a highly exciting and promising avenue for future medical advancements.

Ekhbary News Agency