Waterloo researchers work to bring bone reconstruction into the future

To say that bone grafting is a daunting procedure would be an understatement.

It’s challenging even for top surgeons. And incredibly distressing for patients. The aftermath of these procedures can be just as intense, including months of physical rehabilitation, rejected implants, and infections.

Meanwhile, demand for bone grafts and orthopedic surgery rapidly rises.

People are living longer across the Western world, leading to more age-related conditions like arthritis and fractures. As governments seek ways to serve those rapidly aging populations, solving the challenges of skeletal procedures will become even more critical.

To reduce the risk of complications and improve patient quality of life, University of Waterloo researchers have developed a new method for creating customized bone material.

The solution is a 3D-printable biopolymer nanocomposite that mimics real bone — a material that could eventually become real bone over time.

Yes, that sounds like something straight out of Star Trek, and marks a giant leap toward more personalized skeletal repair.

“With this technology, we can achieve the patient-specific geometry needed to reconstruct bone defects with greater success.”

— Dr. Thomas Willett, Lead Researcher & Professor, Systems Design Engineering

The big idea: 3D printed bespoke bone repair that’s less costly in the long term

For bone grafting, the current surgical toolkit is pretty limited.

When presented with a serious bone injury, surgeons use estimates to determine the bone parameters for the grafting procedure, requesting donor bone segments that roughly fit the patient’s anatomy.

Unfortunately, rejection of donor bone isn’t uncommon. Current methods can also include titanium bone implants, which are strong, but don’t fully integrate with living tissue.

Here’s why the new 3D-printing method provides a lot of hope:

• Featuring bone-like strength and composition, the material is engineered with nanoparticles that mimic natural bone minerals.

• Harnessing 3D printing, the material can be shaped precisely to match the patient’s unique skeletal geometry.

• The material used is biocompatible, so bone cells don’t just tolerate the material, they thrive on it.

• The researchers’ ultimate vision is to enable bio-resorption, so the implant is replaced over time by the patient’s own growing bone.

“We’ve created a material that is strong, 3D-printable and compatible with a potential to become new bone tissue.”

— Dr. Thomas Willett

Early Research with Promising Results

Published in the Journal of Biomedical Materials Research, the study revealed that the new nanocomposite outperforms traditional materials when it comes to bone cell behaviour. They adhere, grow, and function as expected, which is key for any implant that is meant to integrate into living tissue and not be treated like a foreign object.

“The goal is for this material to reduce a patient’s need for repeated operations after undergoing bone reconstruction surgery.”

— Elizabeth Diederichs, PhD Candidate, University of Waterloo

Imagine being able to walk into a hospital, get scanned, and walk out with a custom-printed graft tailored to your exact injury. That’s the level of personalization this new approach could one day support.

If scaled, the new biopolymer nanocomposite could:

• Reduce the risk of implant rejection

• Lower post-surgical infection rates

• Eliminate the need for metal supports

• Reduce hospital stays and long-term complications

• Replace donated bone entirely

Following this early success, the material will now need to clear regulatory hurdles, while clinical trials and funding are next on the researchers’ agenda.

“Any material implanted in the body elicits a response. Our tests show that the biological response of bone cells to our biopolymer nanocomposite outperforms traditional methods. They’re adhering, proliferating and retaining their behaviours, which is very exciting.”

— Dr. Maud Gorbet, Research Collaborator

Global perspectives: patient-centric treatment

The Waterloo team’s work reflects a growing push for healthcare that adapts to the patient, and not the other way around.

As people live longer, the demand for orthopedic surgeries and bone grafts keeps rising, due to age-related conditions like osteoporosis, arthritis, and fracture complications.

• By 2030, nearly 1 in 4 Canadians will be over the age of 65 (Statistics Canada).

• The global population aged 60+ is projected to double by 2050, reaching 2.1 billion people (UN World Population Ageing Report).

• Age-related bone loss (osteoporosis) affects over 200 million people worldwide, leading to 8.9 million fractures annually (IOF).

• As a result of these global trends, the bone grafts and substitutes market is projected to reach US$4.6 billion by 2027, up from $3.2 billion in 2022 (Market Research Future).

The current standards — donor bones and titanium implants or donor bones — aren’t just biologically challenging, they’re also costly and resource-intensive. With millions of procedures performed each year, the potential for a more personalized, regenerative approach is not only more humane and practical but also more economical.

• Over 2 million bone graft procedures are performed annually worldwide (Orthopedic Network News).

• Tissue banks face rising demand and limited donor supply, and custom-matching grafts are often logistically challenging.

• Up to 20% of orthopedic implants may require revision within 10 years, largely due to fit issues, infections, or rejection (Journal of Orthopedic Surgery and Research).

Future in focus: scaling regeneration

If successful, this biopolymer breakthrough won’t just transform orthopedic surgery. It could also create a methodological template for personalized, regenerative treatments across the body.

As 3D printing becomes more scalable, these innovations could eventually reach conflict zones, remote rural clinics, and less-resourced health systems.

For now, the Waterloo researchers remain focused on advancing the material’s strength and regulatory readiness.

Exploring the 15-minute city

The 15-minute city paradigm is gaining ground (and a little heat) these days.

Despite potential pitfalls, the aim of the 15-minute city (and the sustainable, connected urban life that its champions describe) makes the topic ripe for inquiry.

But what exactly is the 15-minute city?

Naturally, it comes down to proximity. It’s an urban planning strategy for building neighbourhoods where residents can access daily needs within a short walking, biking, or transit distance from their homes.

15-minute city proponents argue that a human-centric approach fosters social bonds and builds community by replacing commutes with time spent with family and friends. And by building grocery stores, schools, healthcare facilities, and green spaces within a 15-minute radius, the need for cars is significantly reduced.

As urban populations boom and megacities expand, challenges related to urbanization and social inequality loom. The 15-minute city model appears to offer an intuitive solution, and a study from the University of Toronto sheds a bit more light on the paradigm, using Toronto (North America’s fourth-largest city) as a backdrop.

First steps include reducing reliance on cars

Researchers Anton Yu and Christopher Higgins explored how the 15-minute model impacts travel behaviour across Toronto. Their findings suggest that sustainable travel becomes possible when at least 4-5 essential service and amenity categories are located within close proximity.

Less driving, of course, means less congestion and pollution. So the researchers mapped out access to necessities across the city, revealing varying levels of accessibility and their impact on in-city travel.

“... it is only when neighbourhoods become ‘complete’ in terms of sufficient access to 4–5 categories of amenities that we see rates of driving start to decrease.”

— Yu & Higgins

Core Study Findings

• Neighbourhoods with many accessible amenities had fewer residents relying on cars. Instead, they walked, cycled, or used public transit.

• Central city areas and densely populated areas typically had better access to services. This makes them well-suited for the 15-minute city model.

• Suburban areas lagged behind, indicating a need for improvements in urban planning to extend any benefits citywide.

“... driving rates decrease as sufficient walking, cycling, and transit access improves with the largest decrease associated with sufficient walking access to all five categories of necessities.”

Implications: Ongoing urban planning and transport management

While the paradigm may sound intuitive, the transition to a 15-minute city remains an uphill battle.

To support the 15-minute system, policymakers may incentivize businesses to set up in underserved areas or to improve cycling infrastructure.

The U of T study shows how the success of the 15-minute city will hinge on heavy integration of public transport and land-use planning. From understanding current usage patterns and rethinking zoning laws to transit design — networking all of these variables is crucial.

For example, Toronto has been implementing public transit route improvements and urban revitalization projects like the Bentway. The community space was created beneath one of the city’s major arteries, the Gardiner Expressway. Once derelict, the area now features a skating trail, performance spaces, and gathering spots.

Perhaps the most critical pillar of the 15-minute city remains efficient transit — and it requires near-constant optimization. Toronto has taken some strides to monitor and improve its systems.

For instance, the city’s King Street Transit Priority Corridor project significantly reduced streetcar peak travel times from 23 minutes in 2017 to 16 minutes in 2018. However, by 2023, those travel times worsened to 26 minutes due to widespread construction and weak traffic rule enforcement (with a whopping 6,800+ daily traffic violations). Toronto responded with a crackdown late in the year, deploying traffic agents. By early 2024, travel times during peak hours dropped to as low as 17 minutes when agents were present.

The problem of equal access

The study also highlights a common issue of the 15-minute city model: equality of access. Economically disadvantaged and affluent communities alike need access to quality services. So, it’s a challenge that sometimes requires outside investment. For instance, the United Way’s Greater Toronto Community Hubs have been providing integrated services like health care, education, and social support to underserved areas.

Global perspectives: Growing consensus around the 15-minute city

As a pioneer of the paradigm, Paris implemented the ‘15-Minute Paris’ approach to reduce vehicle use and lower greenhouse gas emissions. Similarly, Melbourne has worked 20-minute neighbourhoods into its long-term planning to encourage physical activity, with the ultimate aim of reducing healthcare costs. Cities like Copenhagen have experienced increases in cycling and pedestrian traffic, which helps support local shops and services.

Of course, the potential scalability and adaptability of the 15-minute model can vary across geographic, economic, and cultural factors. For example, high-density cities like Tokyo or compact European cities like Barcelona may find it easier to implement the 15-minute model compared to sprawling North American cities like Los Angeles and Houston.

Nonetheless, the city of Toronto has provided some valuable insights for others looking to improve urban life with accessible, mixed-use neighbourhoods.

Future in focus: Continuous improvements for greater expansion

As cities grow and evolve, continued research into adaptive strategies will be key:

• Cities like Toronto might address the development of suburban neighbourhoods, which typically have lower levels of accessibility.

• Green infrastructure development and renewable energy projects can also amplify the model’s impact. For example, green roofs, community gardens, and urban forests can help boost quality of life and environmental sustainability.

• Underused spaces like vacant lots or parking areas can be repurposed into community amenities or mixed-use developments.

With continued research and smart investment, high-growth cities like Toronto could serve as a blueprint for others with ballooning populations and growing sustainability requirements.

Are We Ready for the Truth?

The idea that we’re living inside a cosmic computer game has been a staple of pop culture for years. Silicon Valley loves it. Philosophers debate it. Science fiction practically runs on it.

But recent research suggests the simulation hypothesis may be far less plausible than cult theories imply.

Now, math may snap us out of it.

Depending on who you ask, the odds are pretty varied:

• MIT physicist Max Tegmark once estimated that there’s a 17% chance we’re in a simulation

• Philosopher David Chalmers posed that the odds were closer to 42%

When researchers apply Bayesian reasoning and formal statistical analysis, the numbers remain low. Some models suggest the probability could be far below 50%, and possibly negligible.

The Study That May Have Broken the Simulation

Researchers at UBC Okanagan decided to take the simulation idea to its logical conclusion, using tools from physics, logic, and information theory.

The team showed that reality has structural features that no computer could fully reproduce.

“It has been suggested that the universe could be simulated. If such a simulation were possible, the simulated universe could itself give rise to life, which in turn might create its own simulation. This recursive possibility makes it seem highly unlikely that our universe is the original one, rather than a simulation nested within another simulation.”

— Dr. Mir Faizal, UBC Okanagan

The study concludes that the universe appears to be fundamentally built from information, but not all information is computable. This renders algorithms and simulations impossible.

Essentially, they’re suggesting that the universe refuses to cooperate.

The team used a series of theorems (Gödel’s incompleteness theorems, Tarski’s undefinability theorem, and Chaitin’s information-theoretic incompleteness) to show how a fully algorithmic ‘Theory of Everything’ is impossible because some truths about the universe cannot be computed.

Because simulations must be algorithmic, the team argues that the universe can not be a simulation. Any sufficiently powerful formal system contains truths it cannot prove using its own rules.

In pop culture terms, that means:

• A complete description of reality would require non-algorithmic understanding

• That means no finite program can capture everything that exists

• Therefore, reality cannot be fully ‘run’ like software

Hold that thought experiment

Of course, there are contrasting perspectives.

Researcher Evan Redden, for instance, discusses how the Gödelian model doesn’t necessarily imply limits on computation or execution. Using examples like Turing-complete systems, he argues that Gödelian limits don’t automatically break simulation.

In the past, philosopher Nick Bostrom framed the simulation question in probabilistic terms that depend on future tech capabilities. If future civilizations can simulate consciousness and history at scale, then the chance of us being in a simulation increases.

The cosmic video game, unrendered

While recent findings make simulation theory a little less real, it is fascinating that the UBCO team has developed a less abstract process for testing it.

For some, debunking simulation theory could mean our existence is even more magical.

Perhaps our universe is more interesting than lines of code.