Printing Healing Polymers

3d-printer
A standard 3D printer, such as this one, was used to create the polymer drug-delivery implants.

3D printers are being used to create customized controlled drug-delivery implants for patients.

Imagine a 3D-printing technique that could produce a biological implant to transport therapeutic drugs directly to the intended area. Imagine the implant could deliver chemotherapeutic drugs to a tumor to destroy the cancerous tissue. Imagine that after the implant delivered the drugs to the intended target, it would simply degrade safely in the body and be expelled.

It seems a team of research faculty and doctoral students at Louisiana Tech University have let their imaginations run away with them.

Drug-Delivery Breakthrough

The research group from disciplines including the biomedical engineering and the nanosystems engineering programs have developed 3D-printed medical implants that can be loaded with antibiotics or chemotherapy drugs for a more-focused drug-delivery system. This breakthrough could generate improved drug-delivery implants and catheters.

The team created a medical-grade, biodegradable, and biocompatible 3D-printable bioplastic using a filament extruder. The filament extruder can take a polymer resin such as polylactic acid (PLA) or polycaprolactone (PCL) and turn it into a filament that can be used in 3D printing.

Ordinary Equipment

The implants can be printed as single beads, a string of beads, in disc form, or as a fiber. The beads were printed on a standard consumer 3D printer. The print time for the beads was approximately 1-3 minutes, and approximately 5 for the catheter. They are partially hollow to produce more surface area to carry an increased drug load if necessary. The device allows control over the amount of drug delivered to prevent damage to the liver or kidneys. The printing doesn’t stop there. David K. Mills, Ph.D., professor of biological sciences and biomedical engineering, told Polymer Solutions Newsblog:

We can also print syringes, catheters, etc., and all our anti-infective constructs can be loaded with gentamicin, kanamycin, nitrofurantoin — but the method can be extended to many other drugs, including methotrexate, etc.

The inspiration behind the creation of this novel 3D-printing technique was to develop a way to reduce infection, aid in cancer treatment, and to help prevent the spread of disease. The main idea was to freely produce beads and filaments that would reduce infection, as well as provide chemotherapeutic drugs, using a standard 3D printer. The emphasis of the design was based on controlled drug release as far as how much and when. The design would be able to support whatever drugs needed (i.e., antibiotics, antifungals, etc.) to prevent infection and to assist in the treatment for myelodysplastic syndromes (MDS), a bone marrow failure syndrome that typically affects the elderly. It would also be used as an application to treat specific diseases such as cancer.

Current technology employs the use of bone cement as the drug-delivery system. The process is more complicated as the surgeon has to mix the cement in the operating room. The drugs are stirred in and can vary in concentration. The bone cement is applied using a spatula and if trying to fill a weakness or fracture in the bone it doesn’t always fill the imperfection.

The bone cement contains methyl methacrylate (MMA),  a chemical intermediate in the manufacture of Plexiglass, and a possible carcinogen. It cannot be broken down by the body, therefore, a second surgery must be performed to remove the device. On the contrary, the degradation of the new 3-D printed implant inside the body eliminates the need for further surgery.

 Customized Treatment

The latest trend with doctors and pharmacists is the customization of medical products in the treatment of patients. This novel technology can offer them just what they need to deliver personalized care and targeted drug delivery for their patients.

Mills explained to Polymer Solutions Newsblog:

We have also developed a prototype of a 3D print gun. With a 3D scanner, we can image a bone defect, fracture, etc., and then using the scanned image and print gun, completely fill in the defect with resorbable drug-infused materials, bone cement, etc. The key feature here is that the scanned defect is filled in based on the image, and drugs are provided at the right dosage from top to bottom.

The ability to reproduce the design on a standard consumer 3D printer is an added bonus. “One of the greatest benefits of this technology is that it can be done using any consumer printer and can be used anywhere in the world,” said Jeffery Weisman, a Ph.D. student in Louisiana Tech’s biomedical engineering program and one of the researchers involved in the project.

The development of this new technology could revolutionize patient care in hospitals and clinics worldwide. Imagine a world where disease can be controlled by tiny beads and therapeutic drugs. Imagine a world where cancer can be cured. It could just be over that 3D-printed horizon.

Image by tomasmikula/123RF.
Source: “Louisiana Tech Researchers Use 3D Printers to Create Custom Medical Implants,” by Dave Guerin, www.news.latech.edu, August 20, 2014.
Source: “3D-Printed Implants Infused With Medicine to Enable More Effective Drug Delivery,” by Nick Lavars, www.gizmag.com, August 21, 2014.
Source: “Researchers Develop Method for 3D Printing Chemotherapeutic Medicines on Desktop 3D Printer,” by Michael Molitch-Hou, www.3dpritingindustry.com, August 22, 2014.