Ocular bio-lubricating materials: from lubrication mechanism to dry eye syndrome treatment

Q: How does the tear film protect the ocular surface during blinking?

The tear film acts as a multifunctional biological lubricant by combining boundary lubrication (adsorbed mucins and lipids) and fluid film lubrication, thereby minimizing friction and wear and preserving ocular surface integrity.

Q: What happens when ocular lubrication becomes inadequate or dysfunctional?

It can destabilize the tear film and damage the ocular surface, causing dryness, burning, corneal vasodilatation, and culminating in dry eye syndrome with impaired visual function and quality of life.

Q: What characterization tools are discussed for ocular lubrication research?

The review introduces characterization tools such as tribometers, atomic force microscopes, and surface force balances, and compares their working principles, applicable conditions, and fields of application.

Sep 28, 2026

Uploaded by dabgoudw

The review focuses on ocular bio-lubricating materials and explains how the tear film enables the human eye to perform continuous mechanical activity through repeated blinking. Tear film lubrication integrates boundary lubrication from adsorbed mucins and lipids with fluid film lubrication to reduce friction and wear while maintaining ocular surface integrity. Ocular lubrication failure destabilizes the tear film, damages the surface, and drives discomfort, visual dysfunction, and dry eye syndrome. The article links eye structural features and lubricant interactions to friction-related disease mechanisms, then surveys lubrication modes and characterization tools, before outlining DES causes and current bio-lubricants and ocular-inspired materials.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages19

Reading Time48 min

AccessFree to download

Abstract

Introduction

Biological tribology and ocular lubrication

Dry eye syndrome and treatment approaches

Regenerative Biomaterials, 2025, 12, rbaf121 [https://doi.org/10.1093/rb/rbaf121](https://doi.org/10.1093/rb/rbaf121) Advance Access Publication Date: 24 November 2025 Review Ocular bio-lubricating materials: from lubrication mechanism to dry eye syndrome treatment Yanxin Zhang1,2, Suoqi Ding2, Xinyi Wang1,2, Jin Li3, Hao Yu4 and Weifeng Lin1,2, 􀀃 1State Key Laboratory of Bioinspired Interfacial Materials Science, Bioinspired Science Innovation Center, Hangzhou International Innovation Institute, Beihang University, Hangzhou 311115, China 2State Key Laboratory of Bioinspired Interfacial Materials Science, School of Chemistry, Beihang University, Beijing 100191, China 3School of Instrumentation and Optoelectronic Engineering, Beihang University, Beijing 100191, China 4Imeik Technology Development Co. , Ltd. , Beijing 102299, China 􀀃 Correspondence address. E-mail: [linwf@buaa.edu.cn](linwf@buaa.edu.cn) (W.L.) Abstract The human eye, a mechanically dynamic and physiologically vital organ, sustains continuous mechanical activity through repetitive blinking—averaging approximately 20 000 cycles daily, while exhibiting exceptional lubrication performance characterized by an ultralow coefficient of friction (<0.01). This remarkable lubricating functionality is mediated by the tear film, a multifunctional biological lubricant combining boundary lubrication mechanisms (via adsorbed mucins and lipids) and fluid film lubrication mechanisms to minimize friction and wear, and preserve ocular surface integrity. Failure of such ocular lubrication can cause tear film instability or ocular surface damage, leading to discomfort, visual dysfunction and dry eye syndrome. Ocular lubrication involves multiple structures and lubricants with highly complex biomolecular interactions. Insights into the structure of eyes, lubricant composition and causes of functional impairments are essential for addressing friction-related diseases in biological systems. This review examines ocular lubrication by first exploring the biological structure of the eyes and typical lubrication modes. Then, the characterization tools, such as tribometer, atomic force microscope and surface force balance in the field of ocular lubrication, are introduced, followed by a comparison of their working principles, applicable conditions and application fields. Finally, the specific causes of dry eye syndrome are outlined, along with current bio-lubricants, contact lenses and other ocular-inspired bio-lubricating materials. Keywords: bio-lubricants; lipids; hydration lubrication; dry eye syndrome; ocular lubrication Introduction Friction is a universal phenomenon in living and non-living systems. While occasionally advantageous, it often results in energy loss and wear, presenting challenges in industrial engineering [1 , 2] . Lubrication science addresses these issues by systemically developing advanced lubricants and surface engineering strategies to minimize friction losses and ensure the reliability of mechanical systems under operational conditions. Biological tribology, a distinct field from traditional tribology, focuses on human anatomy and health. Conceptualized by Dawson in 1973, biotribology has evolved into a cornerstone of biomedical research, with human biotribology constituting a pivotal subdomain critical for health diagnostics and physiological monitoring. Friction critically influences the functionality of diverse biological interfaces, including the ocular surface, oral mucosa, esophageal lining, intestinal epithelium, vascular endothelia, musculoskeletal tissues (tendons, muscles, articular cartilage) and synovial joints. In healthy individuals, biological lubricants ubiquitously distribute across these interfaces and strategically mitigate shear-induced tissue damage through molecular mechanisms tailored to their microenvironment [3] . Ocular lubrication exemplifies a sophisticated subsystem within this paradigm, where the ultralow

FAQs

How does the tear film protect the ocular surface during blinking?

The tear film acts as a multifunctional biological lubricant by combining boundary lubrication (adsorbed mucins and lipids) and fluid film lubrication, thereby minimizing friction and wear and preserving ocular surface integrity.

What happens when ocular lubrication becomes inadequate or dysfunctional?

It can destabilize the tear film and damage the ocular surface, causing dryness, burning, corneal vasodilatation, and culminating in dry eye syndrome with impaired visual function and quality of life.

What characterization tools are discussed for ocular lubrication research?

The review introduces characterization tools such as tribometers, atomic force microscopes, and surface force balances, and compares their working principles, applicable conditions, and fields of application.

Sep 28, 2026

Uploaded by dabgoudw