The Amazing Biodegradable Material PLA: From Everyday Products to the Biomedical Field

Polylactic acid (PLA), also known as polylactide, is a polyester polymer obtained by polymerizing lactic acid as the main raw material. It is a novel biodegradable material.

Public information shows that PLA is mainly made from starch derived from renewable plant resources (such as corn). The starch raw material is saccharified to obtain glucose, which is then fermented with certain microorganisms to produce high-purity lactic acid. PLA of a certain molecular weight is then synthesized through chemical synthesis. It has excellent biodegradability; after use, it can be completely degraded by microorganisms in nature, ultimately producing carbon dioxide and water without polluting the environment. This is highly beneficial for environmental protection and it is a recognized environmentally friendly material.

PLA has a wide range of applications: From Everyday Products to the Biomedical Field

PLA has good thermal stability, with a processing temperature of 170–230℃. It also has good solvent resistance and can be processed in various ways, such as extrusion, spinning, biaxial stretching, and injection blow molding. Products made from polylactic acid (PLA) are not only biodegradable, but also possess good biocompatibility, gloss, transparency, feel, and heat resistance. They also exhibit certain antibacterial, flame-retardant, and UV-resistant properties, making them widely applicable as packaging materials, fibers, and nonwovens. Currently, they are primarily used in daily necessities (packaging, clothing), industries (construction, agriculture, forestry, papermaking), and biomedical fields.

**Food Packaging:** PLA's excellent transparency, heat resistance, and oxygen barrier properties make it suitable for food packaging. For example, transparent PLA boxes can be used to package fruits, vegetables, and other foods, effectively protecting their freshness and quality. Furthermore, PLA can be used to make disposable tableware such as lunch boxes, cutlery, and straws, replacing traditional plastic tableware and reducing environmental pollution.

**Textiles:** PLA can be blended with other fiber materials to create biodegradable textiles. These textiles can be used to make clothing, bags, and household items. Compared to traditional synthetic fibers, PLA textiles are less irritating to the skin and cause less environmental pollution.

**Textiles:** PLA can be blended with other fiber materials to create biodegradable textiles. These textiles can be used to make clothing, bags, and household items. Compared to traditional synthetic fibers, PLA textiles are less irritating to the skin and cause less environmental pollution.

Agricultural Applications

PLA materials are also widely used in agriculture. For example, PLA can be made into agricultural films for farmland mulching, providing insulation, moisture retention, and weed control. Compared to traditional plastic agricultural films, PLA films are biodegradable after use and do not pollute the soil.

3D Printing

PLA is one of the most commonly used 3D printing materials. Its excellent plasticity and formability allow for the creation of various complex structures using 3D printing technology. PLA used in 3D printing can be pure PLA or a mixture of PLA and other materials, producing models, parts, and crafts.

Medical Devices

Due to its good biocompatibility and biodegradability, PLA is widely used in the medical device field. For example, PLA can be made into sutures, bone nails, and screws for use in orthopedic surgery. During surgery, the PLA gradually degrades, eliminating the need for a second surgery to remove it, reducing patient pain and recovery time.

Biomedical Engineering

PLA materials have broad application prospects in the field of biomedical engineering. PLA materials can be used to create artificial bones, joints, and blood vessels to replace damaged tissues or organs. Due to the biodegradability of PLA, these artificial organs can be gradually absorbed by the body, reducing the risk of secondary surgery.

PLA Production Status and Market in Different Industries

I. PLA in Regenerative Aesthetic Medicine

Because lactic acid is optically active, there are three types of PLA: L-polylactic acid (L-PLA) (PLLA), D-polylactic acid (D-PLA) (PDLA), and racemic polylactic acid (DL-PLA) (PDLLA). PLLA has been used in the medical aesthetics field since 1997.

II. PLA in Orthopedic Implants

Orthopedic implants refer to devices implanted in the human body to replace, repair, supplement, fill, or assist in the treatment of damaged bones, used to maintain, support, and repair human bones. For orthopedic implants, the most researched materials are currently PLA and self-reinforcing biodegradable composite materials such as PGA and PGA/PLLA. Some biodegradable PLA orthopedic materials are already in clinical use.

For example, the tissue-guided regeneration GTR membrane and bone-guided regeneration GBR membrane anchors produced by the Swiss company Geistlich Orthopedics are made from PLA. Suture anchors and implants produced by the American company Linvate, and VICRYL Plus sutures produced by Johnson & Johnson, are also made from biodegradable materials. Before the advent of biodegradable materials, bone repair surgery used traditional repair materials; however, these materials had poor biocompatibility, requiring secondary surgery for removal, which could cause secondary harm to the body. Biodegradable materials, on the other hand, can degrade within the body and suppress local inflammation, making them safe and reliable.

Data released by organizations such as Menet.com shows that the market size of orthopedic implant medical devices in my country is expected to reach 60.7 billion yuan by 2024, with an average annual compound growth rate of approximately 14.51% from 2019 to 2024. Furthermore, data shows that the average life expectancy of Chinese residents has increased from 74.83 years in 2010 to 77.3 years in 2020. The incidence of orthopedic diseases is highly age-related, and the increasing number of elderly people and their growing life expectancy are driving a surge in demand for orthopedic medical devices.

Therefore, PLA has a promising future in the field of orthopedic implantable medical devices.

III. PLA in Drug Release and Control Systems

PLA also plays a crucial role in drug release and control systems. Using PLA as a drug release carrier allows for gradual drug release as the carrier degrades within the body, minimizing harm. Researchers can also leverage PLA's processability to combine drugs with PLA, creating more stable drug release carriers.

With an aging population, the incidence of chronic diseases is rising. Sustained-release and controlled-release formulations can help patients better manage chronic diseases, reducing the severity of symptoms and the occurrence of complications. They can also improve drug efficacy and utilization, reducing waste and side effects. For example, for diabetic patients, sustained-release and controlled-release formulations can slowly release drugs, maintaining stable blood glucose levels and reducing diabetic complications.

In the future, as people's demands for medical technology continue to increase, the market share of sustained-release and controlled-release formulations will continue to grow, thereby driving the development of the PLA-related market.

In conclusion, PLA, as a biodegradable raw material, has broad business opportunities and market prospects under the background of my country's sustainable development. Its increasing demand, expanding profit margins, and the impetus of technological innovation all bring more development opportunities to enterprises.