Surface-modified liposomes: assessment and characterization for increased stability and prolonged blood circulation

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Drug Delivery Systems

Background:

• Liposomes are crucial drug delivery vehicles, but their therapeutic efficacy is limited by biological instability.
• Surface modifications are essential for improving liposome stability, reducing leakage, and preventing premature clearance by the mononuclear phagocytic system.
• Understanding the interplay between surface properties and biological interactions is vital for developing effective liposomal therapeutics.

Purpose of the Study:

• To review recent advances in surface-modified liposomes for enhanced therapeutic applications.
• To critically evaluate in vivo and in vitro study methods used to assess liposome stability and biological interactions.
• To explore the theoretical basis of steric stabilization and its correlation with observed biological properties.

Main Methods:

• Review of in vivo and in vitro studies on surface-modified liposomes.
• Analysis of methods for assessing liposome stability (e.g., leakage, constituent exchange).
• Evaluation of techniques for measuring cellular uptake, particularly by mononuclear phagocytic system cells.
• Investigation of steric stabilization principles and surface coating properties.

Main Results:

• Surface modifications significantly improve liposome biological stability, reducing leakage and unwanted uptake.
• Steric stabilization, achieved through surface barriers, provides a theoretical framework for enhanced liposome performance.
• Correlation between physical properties of surface coatings and biological performance is observed.
• Limitations exist in current assessment methods, highlighting the need for comprehensive characterization.

Conclusions:

• Optimized surface modifications are critical for advancing liposomal drug delivery.
• Steric stabilization is a promising strategy for improving liposome longevity and targeting.
• No single characterization method is sufficient; a multi-measure approach provides the most robust assessment of liposome performance.
• Further research is needed to refine methodologies and fully elucidate structure-property-activity relationships in liposomal systems.