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International Journal of Bioprinting Advancements in 3D printing

lens and the retina, is a clear gel composed of collagen and on the interaction of implant materials with the human
hyaluronic acid, making it a hydrogel tissue with sufficient body gave rise to the second-generation bioceramics,
strength and elastic functions. Hydrogels have been which have been developed into bioactive ceramics that
utilized to make artificial vitreous bodies for addressing can form biochemical bonds with tissues. Porous calcium
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conditions such as vitreous opacity and retinal detachment phosphate bioactive ceramics exhibit osteoinductivity, or
that can lead to vision loss. The hydrogel-based artificial the ability to induce bone tissue formation without the
vitreous body developed by Leone et al. using polyethylene addition of growth factors or living cells, sparking research
glycol/polyvinylpyrrolidone exhibited viscoelasticity and interest in materials for tissue regeneration. Biomaterials
effectively filled and smoothed the retina. Additionally, such as biomedical ceramics can adjust the biological
hydrogels are biocompatible and hydrophilic, and can swell effects of materials by controlling various parameters of the
up after water absorption without affecting their structural material, such as phase structure, chemical composition,
integrity. They can encapsulate bioactive factors, transmit mechanical properties, porous structure, and surface
signals to cells, and support cell culture. As scaffold micro-nanostructure. This regulation can effectively
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materials for tissue engineering, hydrogels can fill defect control the directed differentiation and specific cell
spaces and provide support structures for cell growth and behavior of stem cells, regulate the growth of blood vessels,
function. Furthermore, neural progenitor cells can be and promote the regeneration and repair of damaged
cultured and expanded within hydrogels to create scaffolds tissues. A new generation of tissue-inducing biomaterials
for stem cell culture. Traditional wound dressings such as has been developed based on osteoinductive studies of
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gauze and cotton balls are clinically used because they can porous calcium phosphate ceramics. These materials can
easily adhere to the wound. On the other hand, hydrogels stimulate self-healing functions, allowing regeneration of
emerge as a better option as they provide a high-humidity damaged tissue or organs after implantation.
healing environment while continuously absorbing wound
exudate. The transparency or translucence of hydrogel is Traditional belief suggests that non-living biomaterials
another advantage, allowing wound monitoring, and the cannot elicit tissue formation or organ regeneration.
drug can be embedded in the hydrogel, so that the drug However, recent research developments challenge this
can be gradually and continuously released to the affected notion by showing that tissues and organs can indeed arise
area to promote healing of the wound. Therefore, hydrogel from non-living substances. This perspective represents
dressings have become an increasingly important functional a significant departure from the established concept of
material in the field of skin repair and regeneration in biomaterials. Notably, research on biomedical calcium
recent years. This is also marked by the important phosphate ceramics, which can induce bone tissue
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functions of hydrogels suitable for skin repair, such as formation, has illuminated several novel approaches to
oxygen permeability, physical barrier against bacteria, tissue regeneration. These approaches propose utilizing
absorption of secretions and odor control, mitigation of non-living biomaterials implanted within the human
inflammatory response and blood infiltration, inhibition body to stimulate the regeneration or formation of living
of scar formation, and acceleration of wound healing. tissues and organs. This innovative method is referred to as
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Hydrogels can be used as skin substitutes during wound material-induced tissue regeneration.
healing, protecting the skin while preventing subsequent Biomedical ceramics have found extensive applications
damage, promoting skin regeneration, and accelerating in medical field, including artificial bones, artificial joints,
wound healing. Taken together, hydrogels have great artificial tooth roots, bone filling materials, bone substitutes,
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promise as potential material for facilitating effective tissue engineering scaffolds, artificial heart valves, artificial
wound healing and skin repair (Figure 12).
tendons, artificial blood vessels, artificial trachea, and
3.3. Biomedical ceramic materials prosthetic skin. This versatility has led to their integration
A biomedical ceramic is a specific type of ceramic designed into a wide range of prosthetic and medical devices. From
for medical applications. They represent an important a clinical perspective, the primary objective of utilizing
branch of biomaterials and are the first inorganic non- biomedical ceramic materials is to replace damaged hard
metallic materials used for the diagnosis, treatment, and tissues like bone and dental tissue through transplantation
regeneration of pathological human tissues and organs. techniques, addressing defects and providing mechanical
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Initially, the materials for implantation into the human support. Due to their remarkable physical and chemical
body for tissue replacement and repair were selected similarity to natural hard tissues, biomedical ceramics have
based on the criteria of non-biochemical reactivity and gained prominence in surgical applications, notably in the
high stability, and this resulted in the first generation of fields of dentistry and orthopedics. Alumina and zirconia
bioceramics or bioinert ceramics. However, further research ceramics are among the most notable biomedical ceramics,

Volume 10 Issue 2 (2024) 58 doi: 10.36922/ijb.1752