Ceramics and glass in life sciences

The life science sector benefits from many properties of ceramics, such as inertness, nontoxicity, hardness, high compressive strength, low friction coefficient, wear and chemical resistance, sterile nature, ability to be manufactured with various degrees of porosity, very good aesthetics, and durability. Their brittleness is being mitigated by the introduction of ceramic composites and nanostructured materials, and by processing, for example through hot isostatic pressing. Ceramic coatings are also considered in those cases when there is a need to rely on the substrate’s mechanical strength and toughness.

Ceramics for the human body are called bioceramics. Bioceramics are a class of biomaterials. Biomaterials are materials that do not cause any adverse reaction when they come in contact with living tissue. They can be either bioinert or biocompatible. Bioinert materials coexist with adjacent tissues and react minimally with them (they are almost inert), forming an encapsulation. Biocompatible materials, instead, either form bonds with hard and soft tissues (bioactive materials) or dissolve in the body and generate new tissues (bioresorbable materials). As such, bioceramics can be formulated to be bioinert (e.g., alumina and zirconia), bioactive (e.g., synthetic hydroxyapatite), or bioresorbable (e.g., tricalcium phosphate).

Bioceramics are primarily used for medical implants, either in the form of bulk components or as coatings or fillers. Orthopedic procedures that involve the surgical installment of these implants are aimed at replacing hip, knee, joint, cranio-maxillofacial and spinal hard tissues and are becoming very popular as the world’s population continues to age.

Another relevant application of bioceramics is represented by dental ceramics, which include orthodontic devices (e.g., braces), prostheses (e.g., crowns, bridges) and implants (e.g., all-ceramic root implants). Because they can be made to match the natural color of the tooth, ceramic materials give better results from the standpoint of aesthetics, compared with traditional metal products. With respect to dental implants, ceramic materials offer better osseointegration than titanium and are being engineered to prevent infection and deterioration, particularly through the use of nanomaterials.

Bioceramics are also used to produce components for implantable electronics devices, such as feedthroughs and other elements of pacemakers, defibrillators, neurostimulators, and cochlear implants.

But that is not all. There are several other important applications of ceramics in healthcare, including tissue engineering scaffolds; medical pumps; blood shear valves for hematology testing; drug delivery devices; piezoelectric components for medical tools and instruments; and ceramic-to-metal assemblies for imaging equipment. Also, ceramic particles and microspheres are becoming popular for cancer radiotherapy and other targeted therapies.

As far as glass, the main products from a market standpoint are containers for pharmaceutical use and labware, with emerging applications consisting of microfluidic devices, drug delivery devices, and antibacterial products.

Glass is even used in medical procedures. It is called bioglass and is a bioactive glass that, compared to common soda-lime-silica glass, contains less silica, but has higher Na₂O, CaO, and P₂O₅, three oxides that react with body fluids, forming first a layer of amorphous calcium phosphate and then hydroxyapatite, a crystalline material with characteristics similar to bone cells present in the body.

Various types of bioactive glass-ceramics are also commercially available. Both bioglass and bioactive glass ceramics are chiefly used for bone repair and as dental fillers.

The main applications of ceramics and glass in life science are illustrated in the table below.

Main applications of ceramics and glass in life science

Where?	What?	Examples
CERAMICS
Medical field	Implants	1
	Feedthroughs (Image courtesy Kyocera, fine ceramics division)	2
	Tissue engineering scaffolds	3
	Pumps	4
	Valves	5
	Drug delivery components (Image courtesy Kyocera, fine ceramics division)	6
	Piezoelectric components and tools	7
	Ceramic-to-metal assemblies for instrumentation (Image courtesy Morgan Advanced Materials)	8
Dental field	Orthodontics	9
	Crowns and bridges	10
	Dental implant	11
GLASS
Pharmaceutical field	Containers	12
	EpiPen cartridges (the glass is a borosilicate Type I; chemically strengthened to reduce fracture probability)	13
Biological field	Labware	14
	Microfluidic devices	15
Medical field	Bioglass	16