By Sneha Pakhare
A bioabsorbable polymer can be described as a chemical compound that has crucial applications in orthopedic implant devices. It eventually gets dissolved and gets absorbed by the body. Bioresorbable polymers are ideal materials for prosthetics since their dissolving rate is the same as that of the growth rate of a new bone.
They are extremely elastic and durable compared to stiff metal alloy bone prosthetics, which are known for interfering with bone re-growth.
What are the Major Types of Bioresorbable Polymers?
One of the most popular types of Bioresorbable Polymers includes polylactic acid (PLA), or polylactide. In general, it is the key building block for all bioresorbable polymer materials. Some common derivatives of this type of bioresorbable polymer are poly-D-lactide (PDLA), poly-DL-lactide (PDLLA), and poly-L-lactide (PLLA). In the body, it degrades and turns into lactic acid, which is a non-toxic chemical that happens naturally inside the body.
Polyglycolide (PG), or Polyglycolic acid (PGA)is another key bioresorbable polymer type that is used majorly in bioresorbable sutures. It can be copolymerizedusing lactic acid to develop poly(lactic-co-glycolic acid), or PLGA using e-caprolactone to develop poly(glycolide-co-caprolactone) and more.
Polylactic Acid
PLA is a highly popular polymer material since it is economically developed using renewable resources. PLA is the second most used bioplastic in the world,but its application is hindered by various processing and physical shortcomings.
It is the most extensively utilized plastic filament materialin 3D printing. Its high strength, low melting point, good layer adhesion, high heat resistance, and low thermal expansionwhen annealed render it the perfect material to be used in 3D printing.
What are the Applications of PLA?
Consumer Goods
PLA has uses in different consumer goods like cutlery, disposable tableware, kitchen appliances as well as electronics like handheld devices and laptops, along with microwavable trays. On the downside, PLA can be used in microwavable containers given its low glass transition temperature.It is also used in food packaging, loose-fill packaging material, and compost bags. In the film form, when heated, it shrinks, which allows its use in shrink tunnels. When in fiber form, it has uses in monofilament fishing lines as well as netting. In the nonwoven fabric form, it has uses in disposable garments, upholstery, feminine hygiene products, diapers, and awnings.
PLA also has critical applications in a variety of engineering plastics, in which the stereocomplex is combined with a rubber-like polymer like ABS. Such combinations have impressive form stability as well as visual transparency, rendering them crucial in low-end packaging applications.
PLA has uses in different automotive parts like panels, covers, and floor mats. Its durability and heat resistance are not as good as the widely utilized polypropylene (PP), however; its characteristics are improved when the end groups are capped to bring down hydrolysis.
Medical
PLA completely degrades to turn into lactic acid, which makes it perfect to be used as medical implants that are in the form of screws, anchors, pins, plates, mesh, and rods. Based on the type that is being used, PLA breaks down in the body between 6 months and 2 years. This degradation process is ideal for a support structure since it gradually shifts the load completely to the body while that region is healing. The high strength property of PLA as well as PLLA implants is well-known.Thanks to its biodegradability and biocompatibility, PLA is also used as a polymeric scaffold deployedfor drug delivery purposes.
Polyglycolic Acid
Polyglycolic acid or PGA can be understood as a semi-crystalline, biodegradablethermoplastic, known for its tremendous gas barrier characteristics, excellent biodegradability, and relative high strength. A few grades come with a biodegradation rate that is the same as that of cellulose, which decomposeswhen composted into water and CO2 within a month.
What are the Applications of PGA?
PGA along with its copolymers like poly(glycolide-co-caprolactone) and poly(lactic-co-glycolic acid)have critical uses in numerous applications. Owing to its extremely low permeability to CO2 and O2, it is utilized as a packaging film for products that are sensitive to oxygen. Other crucial applications are shale gas extraction as well as various industrial processes coupled with synthetic fast absorbable sutures used in internal surgeries.
Polycaprolactone
Polycaprolactone or PCL can be described as a biodegradable polyester that has a low melting point of nearly 60°C along with a glass transition temperature of close to −60 °C. Polycaprolactone’s most common use isin the manufacturing of specialty polyurethanes. It imparts excellent resistance to oil, water, chlorine, and solvent to the produced polyurethane.
This bioresorbable polymer is generally deployed as an additive for various resins to enhance their processing properties as well as their impressive end-use properties (such as impact resistance). Given the high compatibility with various other materials, Polycaprolactone can be blended with starch to cut down its cost and elevate biodegradability. It can also act as a polymeric plasticizer when added to polyvinyl chloride or PVC.It is further deployed for modeling, splintingas well as a feedstock for various prototyping systems like fused filament fabrication 3D printers.
Biomedical Applications of PCL
PCL’s degradation happens by the hydrolysis process of its ester linkages in several physiological conditions (like in the human body) and is therefore, subjected to a lot of attention for application in implantable biomaterials. It is especially used for preparing long-termmedical implantable devices, considering that itsdegradation rate is much slower compared to that of polylactide.It finds widespread use in long-term medical implants as well as controlled drug release applications.
Bioresorbable Polymers Market Status Quo
Factors including the mounting number of a variety of surgical interventions, escalating demand for numerous biocompatible medical devices, and the rise in drug delivery applications will favor the worldwide market for bioresorbable polymers in the years to come. The supportive reimbursement scenario, the lower costs associated with bioresorbable polymers compared to traditional polymers, the huge preference for minimally invasive surgeries, and the lenient quality control regulations in developing economies will also benefit the global industry.
A significant opportunity that can emerge in the resorbable polymers industry in the years ahead is the rising demand and development of eco-friendly products that cater to the regulatory standards implemented by numerous environment protection agencies worldwide.
