Recently, Canadian research shows that hydrogel is not only conducive to stem cell transplantation, but also can accelerate the repair of eye and nerve injuries. The research team pointed out that jelly like hydrogel is an ideal medium for stem cell transplantation, which can help stem cells survive in vivo and repair damaged tissues.
This is undoubtedly great news for patients who have been healed by accident or surgery.
Coincidentally, the Pan Haobo team and the researcher Zhao Xiaoli team of the Chinese Academy of Sciences, together with Shenzhen Hospital of the University of Hong Kong and other units, have developed a “stable” injectable adhesive hydrogel (RAAS hydrogel) with both rapid adhesion and anti water absorption swelling, which can quickly adhere to and seal damaged tissues through material design, in combination with “temperature shrinking” nano micelles and “adhesive small molecules” module, Realize effective hemostasis of various bleeding models including cardiac bleeding. At the same time, when used in the spinal cavity, it can seal the dura mater injury, effectively avoid the risk of hydrophilic medical glue swelling and compressing the injured spinal cord tissue, and show the potential application value in spinal surgery healing.
This also represents a major progress in self-healing medicine.
New Material Information NMT | Understanding Hydrogel: Cutting through the thorns&self-healing
As we all know, when an organism is slightly injured, it can rely on its own internal vitality to repair limb defects. This ability to maintain life and health is called self-healing power, but this ability can only occur in living organisms.
Hydrogels also have this self-healing ability in the absence of “life” organic materials. Inspired by the self-healing behavior of human skin and the self-healing behavior of biological mussel secretions, researchers have developed a series of self-healing hydrogels that can self-healing after the material breaks. This self-healing design not only extends the service life of the material, but also restores and maintains its original performance.
Hydrogels are composed of hydrophilic polymers. Their three-dimensional network structure can not only absorb a large amount of water, but also be used to carry drugs. Hydrogels prepared with suitable materials have the characteristics of high biocompatibility, controllable mechanical and viscoelastic properties.
The earliest date can be traced back to 1894, and it was initially used to describe some inorganic salt colloids. Over time, the meaning of hydrogel is completely different from that of the beginning. The first mature hydrogel product in the world, Ivalon (cross-linked compound of formaldehyde resin and ethylene), came out in 1949, and PHEMA (polyhydroxyethyl methacrylate) came out in 1960, which promoted the market of hydrogel to prosperity.
New Material Information NMT | Understanding Hydrogel: Cutting through the thorns&self-healing
In 1960, WiChterle and Lim first synthesized crosslinked HEMA hydrogel. Its hydrophilicity and potential biocompatibility aroused great interest of biomaterials scholars, which led many researchers to carry out a lot of research on improving the performance of hydrogel. It is widely used in biomedical fields such as drug delivery carriers, ophthalmic materials, medical dressings and cosmetic materials.
Drug release carrier
The hydrogel has good permeability to small molecule water-soluble solutes, which can keep the loaded substances active for a long time, and at the same time ensure the long-term release of drugs in the body. In addition, the hydrogel material for embedding drugs can be transplanted or injected to the designated location of the organism, thereby enhancing the targeted efficacy of drugs. Therefore, hydrogels become intelligent carriers for controlling drug delivery systems.
Ophthalmic materials
The vitreous body of the eye is gel shaped, and the matrix of the gel is collagen and hyaluronic acid, which is a hydrogel tissue with sufficient strength and elasticity. Both vitreous opacity and retinal detachment can cause vision loss or even blindness. In order to overcome the turbidity and inadaptability of the artificial vitreous body, Leone et al. prepared polyvinyl alcohol/polyvinyl pyrrolidone based hydrogel. The hydrogel has viscoelasticity and shows a good filling effect. It can seal the hole, flatten the retina and be used as an artificial vitreous body.
Tissue engineering scaffold
Hydrogel has excellent biocompatibility and hydrophilicity. It can not change its own structure while absorbing water and swelling. It can be used to wrap bioactive factors to transmit signals to cells and culture cells. As a supporting structure for cell growth and function, it can fill the defect space. These characteristics enable hydrogel to become an ideal scaffold material and be used as a scaffold for tissue engineering. Ashton et al. prepared a alginate salt water gel that can adjust the degradation rate by mixing the copolymer microspheres loaded with alginate lyase into the alginate salt water gel, loaded neural progenitor cells (NPC) into the hydrogel, cultured and expanded in vitro, and used it as the culture scaffold of stem cells.
Medical dressings and cosmetic materials
Traditional wound dressings such as gauze and cotton ball have certain protective effects on the wound, but they have certain limitations in clinical use due to their easy adhesion to the wound surface. The hydrogel has a high moisture content, which can provide a relatively wet healing environment for the wound, and can continuously absorb the wound secretion. At the same time, the transparent or translucent appearance of the hydrogel is convenient for observing the wound healing, and different drugs can be embedded in the hydrogel as required, and the drugs can be slowly and continuously released to the lesion area, so as to achieve the purpose of curing the wound or skin disease.
These characteristics make hydrogel dressings become the most competitive functional materials in medical fields such as wound care and skin repair and regeneration in recent decades, and show a growing trend year by year.
At present, the main local manufacturers in the Chinese market include Changchun Jiyuan Biotechnology, Zhuhai Guojia New Materials and Huizhou Huayang Medical Devices. The products of Fusangdi Pharmaceutical, the production base of Imperial Japan Pharmaceutical in Qingdao, are not only supplied to the local market, but also exported to Japan, South Korea, Southeast Asia and other Asia-Pacific regions. 3M and ConvaTec are the main import brands in China. ConvaTec used to be the most popular product in China. In 2020, the sales volume of the top five enterprises in China reached 60.91% of the total market, with a high market concentration.
In 2020, the market size of medical hydrogel in China will reach 547 million yuan, which is expected to reach 714 million yuan in 2026, with a CAGR of 4.52%.
In the past ten years, the national policies have given great support to the hydrogel industry, so some landmark achievements and progress have been made. However, due to the lack of systematic and in-depth basic research, the lack of mastery of key methods and technologies, and the lack of a corresponding engineering industrialization platform, the development of the gel industry is facing many difficulties, lacking international competitiveness.
From the perspective of national strategy, the establishment of gel engineering technology research center plays a crucial role in promoting and promoting the achievement transformation and industrialization capacity of China’s gel industry, meeting the huge demand of China’s new materials and related industries, forming independent intellectual property rights and international competitiveness, actively expanding the international market, creating greater benefits of gel industry and even national economic development.
In any case, hydrogels have existed for more than half a century, but their charm is still beyond doubt. Due to its unique characteristics, hydrogels have always attracted the attention of the pharmaceutical industry. Although the relevant theoretical research has deeply explored its entry, there are still many prescriptions that have failed to enter the market, and hydrogels are still promising in the field of drug delivery.
“The implanted biomaterials perform well in patients as well as in the laboratory, so we hope that this method can become a routine measure for nursing and promoting self-healing.” In fact, this achievement is also a concept demonstration experiment. To prove the safety, effectiveness and clinical value of hydrogels, more time and large-scale experiments are needed.
In fact, this discovery has potential application value in many fields related to biology and medicine. We can only wait and see where the future research and application will go.