An initiation to the modification of polymers
Modification or attachment of the protein or other molecules with synthetic polymers can provide many benefits for both in vivo and in vitro applications. Covalent coupling of polymers to large macromolecules can alter their surface and solubility properties, creating increased water solubility or even organic solvent solubility for molecules normally sparingly miscible in such environments. Polymer modification of foreign molecules can provide increased biocompatibility, reducing the immune response and increasing in vivo stability.
Polymers are modified to increase their properties susceptible to be applied in various applications. Scientists have been contriving different methods for years to modify polymers.
An occurrence of the synthetic polymers
For instance, several polymers are used in bone tissue engineering as implants or scaffolds to enhance cell attachment, proliferation, and activity, leading to shorter healing time of injured or missing tissue. Amongst the most common synthetic polymers used for these purposes are biodegradable polyesters Polylactic Acid (PLA), and inert polymers Polyether ether ketone (PEEK).
Surface Modification Methods
The techniques used recently to modify polymer are broadly classified into two categories, such as,
- Physical Modification
- Chemical Modification
The following methods are studied under physical modification. These are listed as follows-
- Plasma spray coating
- Photochemical deposition
- Radiofrequency magnetron sputtering coating
- Aerosol deposition
- Electron beam deposition etc.
The following methods have been used for chemical modification. These are named as follows-
- Covalent Grafting
The chemical methods stated above are practiced through the following chemical processes shown as examples-
- Alkali Hydrolysis
Drawbacks of surface modifications
Recent methodologies to modify polymer mostly rely on adsorption, plasma or hydrolysis. The drawbacks include the followings-
- Formation of the non-cohesive layers on the surfaces
- Non-uniform modification
- Degradation of the polymer structure during modification
In addition, many of the methods do not allow for the modification of materials with complex geometries and are quite expensive, requiring specialized equipment.