Category: Biomedical Research

Introduction

Bioglass is an innovative biomaterial renowned for its bioactivity and ability to bond with bone and soft tissues. This class of bioactive materials, composed mainly of silica (SiO₂), calcium oxide (CaO), sodium oxide (Na₂O), and phosphorus pentoxide (P₂O₅), has seen significant advancements in recent years. Originally developed for bone regeneration, bioglass is now at the forefront of medical applications, including tissue engineering, antimicrobial coatings, and drug delivery systems. These advancements stem from cutting-edge research in surface modifications, composite materials, and functional coatings that enhance the properties and applications of bioglass in the biomedical field.

The Chemistry Behind Bioglass

The bioactivity of bioglass is rooted in its chemical composition and the reactions it undergoes upon exposure to physiological fluids. When a medical professional implants bioglass into the body, it undergoes a series of reactions starting with the leaching of sodium and calcium ions, which raises the pH, initiating the formation of a silica gel layer on the glass surface. This gel layer serves as a template for the nucleation of hydroxyapatite, the mineral phase of bone. Simultaneously, the release of calcium and phosphate ions into the surrounding tissue aids the deposition of new bone minerals, thus bridging the gap between the implant and the natural bone. Recent innovations have fine-tuned this process by introducing dopants like magnesium, strontium, and zinc. These dopants enhance the bioactive response, improve mechanical strength, and tailor the degradation rates to match tissue healing processes.

Surface-Modified Bioglass

Recent studies, such as those published in the Journal of Nanoparticle Research, have focused on enhancing the bioactivity of bioglass. By altering the surface chemistry, researchers have significantly improved the material’s antibacterial properties and its ability to promote angiogenesis ( the formation of new blood vessels, which is critical for tissue regeneration). Surface modifications, such as the incorporation of silver, copper, or zinc ions, make bioglass more effective in preventing infections in implanted materials. These ions disrupt bacterial cell walls, leading to cell death, while simultaneously promoting the formation of hydroxyapatite—one of the key components in bone mineralization. This dual function of bioglass is crucial in applications such as bone regeneration and wound healing.

Copper-Based Composites: Expanding the Horizons of Bioglass Applications

In addition to traditional applications, bioglass has found novel implementations in advanced electronic and biomedical devices through the development of copper-based composites. A study published in Nanoscale Advances revealed that incorporating nano-sized particles into copper matrices enhances the material’s mechanical strength, thermal stability, and electrical conductivity. These properties are crucial for next-generation electronic packaging and biomedical devices that demand both durability and high performance. The use of such composites is particularly promising for developing multifunctional implants and devices that require both bioactivity and robust mechanical properties​. The copper ions also play a role in angiogenesis, further supporting tissue regeneration.

Advanced Bioactive Glasses

The field of tissue engineering has benefited immensely from the development of novel advanced bioactive glasses. Recent breakthroughs involve the integration of elements such as strontium and boron into bioglass. Strontium ions mimic calcium ions and are readily incorporated into new bone tissue, where they not only enhance bone density but also slow bone resorption by inhibiting osteoclast activity. Boron, on the other hand, improves the glass’s solubility, allowing for more controlled degradation rates, which is essential for the gradual release of therapeutic ions. These additions not only enhance the material’s ability to regenerate bone but also improve its antibacterial activity. This dual functionality is essential for preventing infections and promoting the rapid healing of bone defects, making bioglass an increasingly attractive option for orthopedic and dental applications.

Functional Coatings and Hybrid Materials: Paving the Way for Next-Generation Implants

Bioglass is also being explored in combination with other materials to create hybrid systems that offer enhanced properties. For example, integrating bioglass with hydroxyapatite has led to improved osseointegration (the formation of a direct interface between an implant and bone, without intervening soft tissue) and mechanical strength. The hydroxyapatite layer mimics natural bone minerals, promoting the adhesion and proliferation of cells that form and heal bones (osteoblasts), while the bioglass beneath continues to release ions that support bone growth and fight infection. These hybrid materials are particularly useful in the development of long-lasting implants and prosthetics, where both bioactivity and mechanical integrity are crucial. The ongoing research in this area suggests that such multifunctional materials could revolutionize the design and functionality of future biomedical devices​.

Conclusion

The evolution of bioglass technology is a significant leap forward in biomedical science. The innovations in surface modifications, composite materials, and hybrid systems not only enhance the performance of bioglass in traditional applications but also expand its potential into new therapeutic areas. As research continues to advance the boundaries of what bioglass can achieve, it is poised to play a transformative role in regenerative medicine, tissue engineering, and beyond. The future of bioglass is bright, with its applications extending well beyond the realm of bone regeneration, into the development of smarter, more effective biomedical devices.

Introduction

Antimicrobial resistance (AMR) occurs when bacteria, viruses, fungi, and parasites evolve to become drug-resistant, pushing antibiotics and other antimicrobial medicines to practical obsoletism and thus increasing the difficulty of infection treatment. The prevalence of AMR is a pressing issue, cited by the World Health Organization (WHO) as one of the top 10 global public health threats facing humanity.

A promising threat to AMR is the use of “phage therapy”, a method of utilizing bacteriophages (phages) to eliminate specific bacterial strains.

Phages are viruses of bacteria that evolve to be extremely specialized, targeting only their certain type of bacterial cells and not affecting human cells. This opens a door for phage therapy to be used within the human body against bacterial infections, rather than solely antibiotics.

In the 1940s, the Western world saw chemical-based small-molecule antibiotics usurp potential research into phage therapies. Continued research into the potential of phage therapy allowed members of the former USSR to harness bacteriophages to treat disease. Phage therapy is now commonplace in Eastern Europe, specifically in Russia and Georgia where it is offered over-the-counter.

Dependency upon antibiotics has resulted in a fight against antimicrobial resistance, however, phage therapy may just be the method to bring us out of it.

Advantages of Phage Therapy

Bacteriophages occur abundantly on Earth, from the water of the oceans to the human GI tract. To attack bacterial cells, phages initiate the lytic cycle, wherein they first puncture the bacterium and then inject their own genetic information. The cell becomes a metaphorical warehouse for new phages, producing and assembling phages until the cell is full. Phages within the cell release endolysin, an enzyme that signals the end of the lytic cycle and causes the bacterial cell to explode, releasing brand-new phages.

There are many advantages to employing phage therapy over traditional antibiotic approaches.

Bactericide:

Phages are bactericidal, meaning they kill their host bacteria. However, some antibiotics are only bacteriostatic and cause a bacterium to become stuck within its stationary phase of growth rather than killing it, leaving behind the viable cell and opening a pathway for potential AMR.

Dosage:

As phages undergo the lytic cycle they self-amplify in an exponential fashion, which could potentially allow for a phage therapy to be effective with single or very low dosages. Lingering in the body after infection is not a worry, as phages only continue to multiply as they are killing bacteria.

Flora Bacteria:

Normal flora bacteria, “good” bacteria of the body, do not generally fall into the extremely specific target ranges of phages, which means they are almost totally unaffected by their presence in the human body. When antibiotics are introduced into the body, however, they tend to wreak havoc on any bacterium they come into contact with, including the normal flora that inhabits our bodies and aids us in many everyday functions.

Resistance:

When bacteria develop resistance to a chemical-based antibiotic it resembles an en masse revolt against one “villain”. Yet, bacteria find it relatively more difficult to develop resistance against phages due to their specific host ranges, since there is no single “villain”. Additionally, as bacteria evolve against phages, the phages have the capability to evolve right along with them, protecting the body against any bacterial strains that develop resistance.

FDA Approval

While phage therapy seems a promising opportunity, the US Food and Drug Administration (FDA) agency has yet to approve any therapies. As phage therapies are classified as biological products by the FDA, any manufacturing needs to adhere to standards like GMP, preclinical research, and all stages of clinical trials. This approval process is a tedious effort, however, as of October 2023 the US has the most phage-related Industry-Sponsored Trials (ISTs) on the worldwide scale, showing there is significant industry-related innovation on this front. Some examples of promising phage therapies in clinical trials within the US include WPP-201 for chronic venous leg ulcers and PreforPro for gastrointestinal distress.

Some of these ISTs are in their third phase of clinical trials, wherein the phage therapies are being tested for large-scale efficiency and comparison to currently market-available competitors. This is the final stage of testing prior to a drug or treatment to be submitted to the FDA for approval.

Despite the many advantages of phage therapy, there is still room for major disadvantages that are avoided through thorough testing prior to FDA approval. Namely, phages possess a narrow host range, inherent biological nature, and unfamiliarity within traditional Western medicine. For these reasons, along with the lengthy approval process, there is still time to go before Americans see phage therapies available to them for treatment.

Although the 1940s saw a shift away from bacteriophage research within Western countries, as time progresses, they could still very well be our savior from the self-inflicted antimicrobial resistance crisis.