Scientists have figured out how to grow human liver cells in the lab without using animal serum—a common ingredient that comes from animal blood. This is important because animal serum can vary from batch to batch and raises ethical concerns. The researchers created a special recipe of nutrients and chemicals that works just as well as animal serum for growing 3D clusters of liver cells. These lab-grown liver cells behaved normally and could be used to test how drugs work in the body. This breakthrough means scientists can do better research without relying on animal products, making experiments more reliable and ethical.

The Quick Take

  • What they studied: Can scientists grow human liver cells in a lab using only plant-based and synthetic ingredients instead of animal blood serum?
  • Who participated: The study used primary human hepatocytes (fresh liver cells from human donors) grown in 3D spheroid cultures (tiny ball-shaped clusters). No human subjects were involved—only laboratory cell cultures.
  • Key finding: Liver cells grown without animal serum performed just as well as those grown with it. The cells stayed healthy, functioned normally, and could process drugs the same way a real liver does.
  • What it means for you: This research helps scientists test medicines more reliably and ethically. If you take medications, this means future drug testing could be more accurate because it uses better lab models. However, this is still early-stage research, and animal testing will likely continue for some time.

The Research Details

Scientists took human liver cells and grew them in special 3D clusters called spheroids. They created a new growth medium (the liquid that feeds the cells) made entirely from plant-based and synthetic ingredients, replacing the traditional animal serum that’s usually used. They tested two versions: one with normal blood sugar and insulin levels matching a healthy person’s body, and another with different levels. The researchers then compared how well cells grew in their new animal-free medium versus the traditional animal serum medium.

To evaluate success, they looked at several things: whether the cells stayed alive and healthy, how the cells looked under a microscope, and whether the cells could perform their normal job of processing drugs. They also used advanced protein analysis to see if the cells were functioning normally at a molecular level.

This approach is important because it creates what scientists call a ‘chemically defined’ system—meaning they know exactly what ingredients are in the growth medium, with no mystery components from animal blood.

Animal serum has been the standard for growing cells in labs for decades, but it has major problems. Each batch of animal serum is slightly different, which makes it hard to compare results between experiments. Additionally, animal serum raises ethical concerns because it comes from animal blood. By developing an animal-free alternative that works just as well, scientists can do more consistent, reliable research while also addressing ethical concerns about animal use in research.

This study demonstrates strong scientific rigor through multiple evaluation methods. The researchers didn’t just look at whether cells survived—they used advanced proteomics (studying all the proteins in cells) to confirm the cells were functioning normally. The fact that the serum-free cells performed comparably to traditional cultures on multiple measures suggests the results are reliable. However, the study focused on demonstrating proof-of-concept rather than testing on a large scale, so further validation in different labs would strengthen confidence in the findings.

What the Results Show

The main discovery is that human liver cells grown without animal serum stayed just as healthy and functional as cells grown with animal serum. The cells maintained normal viability (they didn’t die at higher rates) and continued to perform their key job: processing drugs through special proteins called cytochrome P450s. These proteins are crucial because they’re how your body breaks down medications.

The researchers used a special recipe that included plant-based growth factors and synthetic hormones, particularly insulin at levels that match a healthy human body (0.58 ng/mL). This physiologically relevant approach—meaning it mimics what actually happens in a real human body—appears to be key to the success.

When scientists examined the proteins in these cells using advanced analysis, they found the cells were functioning normally at a molecular level. This is important because it means the cells weren’t just surviving—they were actually working properly. The serum-free cultured cells showed comparable performance to traditional cultures, suggesting they could be used for long-term studies and drug testing.

The study also demonstrated that the animal-free medium could support extended culture periods, meaning cells could be grown and studied for longer without degrading. The morphological evaluations (how the cells looked and were shaped) showed that 3D spheroid structures formed properly without animal serum. Additionally, the chemically defined nature of the medium means researchers can now precisely control and understand every component, which wasn’t possible with animal serum that has unknown variable components.

This research builds on previous work showing that animal-free substitute cocktails could work for cell cultures, but this is the first demonstration that these substitutes work specifically for 3D primary human liver cell spheroids with physiologically relevant hormone and nutrient levels. Previous attempts to replace animal serum often resulted in reduced cell performance or required frequent optimization. This study shows that with the right formula, performance can be maintained while eliminating animal products entirely.

The study doesn’t specify the exact number of cell cultures tested or provide detailed statistical comparisons between groups, which would strengthen confidence in the results. The research focuses on demonstrating that the approach works but doesn’t extensively test how it performs across different donor sources or in all possible drug-testing scenarios. Additionally, while the cells performed well in this controlled lab setting, real-world application in pharmaceutical companies and research institutions will require further validation and standardization. The study also doesn’t address whether this approach works equally well for all types of liver cell studies or only specific applications.

The Bottom Line

For researchers and pharmaceutical companies: Consider transitioning to animal-free culture media for liver cell studies, particularly for drug metabolism and toxicity testing. This approach appears reliable based on current evidence (moderate confidence level). For the general public: This research supports more ethical and reliable drug testing methods, which may eventually lead to safer medications. However, expect that full transition away from animal testing will take several years.

Pharmaceutical researchers and drug development companies should care most about this finding, as it directly impacts how they test new medications. Regulatory agencies that oversee drug approval may find this valuable for establishing new testing standards. Animal welfare advocates will appreciate the ethical advancement. Patients taking medications should care because better lab testing methods may lead to safer, more thoroughly tested drugs. This research is less directly relevant to individual consumers making daily health decisions, though it supports the broader goal of better drug safety.

This is foundational research, so don’t expect immediate changes in how drugs are tested. Typically, it takes 3-5 years for new laboratory methods to be validated and adopted by pharmaceutical companies. Regulatory acceptance might take another 2-3 years. Within 5-10 years, we may see wider adoption of animal-free testing methods in drug development, potentially leading to more reliable medications reaching the market.

Want to Apply This Research?

  • Track medication side effects and effectiveness over time. Users can log which medications they’re taking, any side effects experienced, and how well the medication is working for them. This real-world data helps validate whether lab-tested drugs perform as expected in actual patients.
  • Users could set reminders to report medication effectiveness and side effects weekly. This creates a feedback loop where users become aware of how their medications are actually working, potentially improving medication adherence and communication with healthcare providers about drug performance.
  • Implement a long-term medication tracking system where users can compare their experiences with medications over months and years. This helps identify patterns and provides valuable data that could eventually contribute to understanding real-world drug performance beyond what lab testing alone can reveal.

This research describes laboratory methods for growing human liver cells without animal products. It is not medical advice and does not directly apply to personal health decisions. The findings are relevant to pharmaceutical researchers and drug developers, not to individual patients. If you have questions about your medications or how they were tested, consult your healthcare provider. This study represents early-stage research; widespread adoption of these methods in drug testing will take several years. Always follow your doctor’s guidance regarding medications, regardless of testing methods used in their development.