Microplastics in organ transplantation: An emerging threat requiring immediate action

Abstract

Microplastic contamination has emerged as a threat in transplantation, with evidence of its presence in human tissues and potential to compromise grafts. Transplant recipients, vulnerable due to immunosuppression and surgical exposure, face risk from microplastics via airborne particles, surgical materials, and organ preservation systems. These particles trigger inflammation, oxidative stress, and immune dysregulation—pathways critical in rejection. Microplastics support biofilm formation, potentially facilitating antimicrobial resistance in clinical settings. Despite this risk, transplant-specific research is lacking. We urge action through environmental controls, material substitutions, and procedural modifications, alongside research targeting exposure pathways, biological impact, and mitigation strategies. Transplantation has historically led medical innovation and must do so in confronting this environmental challenge. Leadership from global transplant societies is essential to protect recipients and ensure safe procedures.

Key Words: Microplastics; Surgery; Transplantation; Organ; Healthcare

Core Tip: Microplastic contamination poses a hidden risk in organ transplantation, with potential to trigger inflammation, oxidative stress, and antimicrobial resistance. This letter calls for urgent research and immediate mitigation strategies, urging the transplant community to lead proactive responses to this emerging threat.

TO THE EDITOR

Hidden contamination crisis

The ubiquity of microplastics in our environment has reached a critical threshold that can no longer be ignored by the transplant community. Microplastic particles, measuring less than 5 mm, have infiltrated every biological system on Earth, from marine ecosystems to human tissues[1]. Recent studies have detected microplastics in human blood, placenta, lung tissue, and atherosclerotic plaques, with concentrations highest in lipophilic environments where they accumulate preferentially[2,3].

THE TRANSPLANTATION VULNERABILITY WINDOW

Organ transplantation represents a convergence of multiple risk factors that amplify microplastic exposure beyond typical surgical interventions. Recipients face a triple burden: Compromised immune systems, direct organ contamination pathways, and extended exposure during complex procedures from multiple sources and exposure pathways.

The surgical environment itself becomes a microplastic generation zone[4]. Sterile packaging, perfusion lines, sutures, surgical films, and even implantable devices release particles through mechanical stress, thermal processes, and degradation which can be transported directly by surface-to-surface transfer or indirectly through the air[5-8]. Unlike other surgeries, transplantation involves direct tissue transfer, potentially carrying microplastics from donor preservation systems directly into the recipient.

Current evidence suggests microplastics trigger inflammatory cascades, oxidative stress, and immune system dysregulation - precisely the pathways transplant recipients struggle to manage[9-11]. Lipid peroxidation, resulting from the elevated reactive oxygen species and lipophilicity of microplastics, is a key mechanism of microplastic toxicity and poses particular concern especially given the lipophilic nature of many immunosuppressive protocols.

Liver and kidney grafts are among the most frequently transplanted organs and may be vulnerable to microplastic contamination through airborne exposure or direct and indirect contact with plastic-based consumables during organ acquisition and surgical procedures. Experimental studies indicate that microplastics, such as polystyrene, can impact human kidney (HEK 293) and liver (Hep G2) cell lines by reducing cellular proliferation, causing morphological changes, and increasing ROS generation, all while maintaining their viability. The downregulation of key antioxidant factors, including superoxide dismutase 2 and catalase, has also been implicated in exacerbating this impairment of cellular metabolism[12]. Moreover, exposure to microplastics can disrupt immune cell function, leading to inflammation, which is concerning given the need to minimize graft immunogenicity and post-transplant responses[13].

KNOWLEDGE GAPS DEMANDING INVESTIGATION

Despite growing evidence of microplastic bioaccumulation, transplant-specific research remains virtually absent. Critical questions require immediate investigation:

Exposure pathways

What are the relative contributions of airborne vs contact transmission? How do preservation solutions and perfusion systems contribute to organ contamination? Which plastic types and sizes pose greatest risk? Research studies have yet to explore microplastic surface contamination in healthcare settings beyond air and dust. This represents a significant research gap and strengthens the urgent need for hospital-specific research on surface deposition of microplastics.

Biological impact

How do microplastics interact with immunosuppressive regimens? Do they exacerbate rejection pathways or interfere with graft acceptance? What are the long-term accumulation patterns in transplanted organs?

Source identification

Which surgical materials contribute most significantly to exposure? How do sterilization processes affect particle generation? What contamination occurs during organ procurement and transport?

Potential for anti-microbial resistance

It is known that microplastics provide a favorable environment for biofilm formation[14]. Recent studies have raised the concern that biofilms on microplastics in hospital settings can facilitate horizontal gene transfer, leading to anti-microbial resistance, or a protective environment against disinfection actions[4,15].

IMMEDIATE ACTIONS FOR RISK MITIGATION

While research progresses, the transplant community can benefit from implementing practical and actionable measures as it awaits findings and definitive proof from large-scale studies. Several practical interventions can help to reduce microplastic exposure in the short term:

Material substitution

Replace high-shedding plastics with alternatives where clinically appropriate. Prioritize non-plastic materials for high-contact applications[6,16]. Select plastic types with lower particle generation potential[7].

Environmental controls

Implement enhanced air filtration systems specifically designed for microplastic capture[17]. Establish rigorous surface cleaning protocols beyond standard disinfection. Monitor air quality during procedures using real-time particle counters[18].

Procedural modifications

Minimize unnecessary plastic usage during critical transplant phases[19]. Optimize packaging timing to reduce airborne particle generation. Consider specialized ventilation protocols for organ preparation areas.

Evidence-based solutions still need to be developed to support safe and sustainable by-design interventions in the future.

A FRAMEWORK FOR SYSTEMATIC INVESTIGATION

We propose a coordinated research initiative addressing three interconnected domains:

Exposure assessment

Comprehensive mapping of microplastic sources, concentrations, and transmission pathways in transplant environments. Comparison of exposure pathways (i.e., airborne vs contact transmission) and identification of the most problematic. This includes real-time monitoring during procedures, surface contamination studies, and donor organ analysis.

Biological impact studies

Investigation of microplastic interactions with immunosuppression using relevant animal models and clinical biomarker studies. Focus on inflammation, oxidative stress, and graft function parameters. Regional accumulation of microplastics in patient and donor organ.

Intervention evaluation

Systematic testing of mitigation strategies, from material substitutions to environmental controls, with quantitative exposure reduction metrics. Estimation of changes in the rate of microplastic release resulting from the operation theatre conditions, e.g., pH, UV sources, temperature, solvent concentration.

Standardized measurement protocols must be established, focusing on clinically relevant size ranges (1-20 μm) and surface area metrics for nanoscale particles. Collaboration with the broader microplastics research community will accelerate method development and ensure consistency with environmental health initiatives.

THE IMPERATIVE FOR LEADERSHIP

The transplant community has historically led medical innovation through rigorous attention to emerging risks. From infection control to tissue compatibility, transplant medicine has pioneered approaches later adopted across healthcare. Microplastic contamination represents the next frontier requiring this same proactive leadership.

CONCLUSION

The convergence of environmental contamination with our most vulnerable patients demands immediate attention. Every transplant procedure potentially introduces microplastics into recipients already managing complex medical challenges. The long-term consequences remain unknown, but the precautionary principle suggests urgent action is warranted. We call upon the European Society for Organ Transplantation, the American Society of Transplant Surgeons, the Transplantation Society, and the global transplant community to prioritize this issue through dedicated conference sessions, research funding initiatives, and collaborative multidisciplinary investigation protocols. The health of our patients and the integrity of transplanted organs may depend on actions taken today. The time for awareness has passed. The time for action is now.