Liposome Panorama Guide: Definition, Structural Mechanisms, Applications, and Selection Workflow (Including Products Table 1–Table 3)

1) What is a liposome?

A liposome can be understood as a small vesicle formed by the self-assembly of lipids (most commonly phospholipids) into a lipid bilayer. The vesicle contains an aqueous interior (water phase), and its exterior consists of one or multiple lipid bilayer membranes.

Note: The signature structure of a liposome is an aqueous core enclosed by a lipid bilayer. By contrast, micelles are typically single-layer aggregates and do not have an aqueous core wrapped by a bilayer.

Everyday analogy: It is somewhat like a “soap bubble,” but the “bubble wall” is not made of soap molecules. Instead, it is a phospholipid bilayer membrane—more like a one- or multi-bilayer phospholipid vesicle suspended in water.

2) What is special about the structure, and why can it “carry cargo”?

The structural advantages of liposomes come from two aspects:

A. Amphiphilicity-driven self-assembly: membranes form naturally

• Phospholipids are amphiphilic: one end is hydrophilic and the other hydrophobic. In water, they spontaneously arrange into a bilayer—hydrophilic heads facing the aqueous environment and hydrophobic tails facing inward toward each other—forming a stable membrane.
• Note: Not all lipids form stable bilayers. Whether a stable bilayer forms depends on molecular geometry and phase behavior. For example, DOPE tends to favor non-lamellar (inverted hexagonal, HII) phases under physiological conditions. Therefore, it is often used as an auxiliary lipid to promote fusion and/or endosomal escape, rather than being used alone as a stable bilayer “backbone.”

B. It has both an aqueous core and a lipid membrane: two cargo types can be loaded

• Hydrophilic molecules: More readily enter and become encapsulated in the internal aqueous compartment. Hydrophilic payloads are typically “trapped” in the internal water phase during preparation/hydration. Once the liposome is formed, hydrophilic molecules generally do not readily diffuse across the membrane to enter on their own (unless membrane permeability is high or special loading strategies are used).
• Hydrophobic molecules: More readily partition into the hydrophobic region of the lipid bilayer, which is one major reason liposomes are widely used as carriers for drugs and biomolecules.

Note: Hydrophobic payloads can distribute into the bilayer’s hydrophobic region, but the loading amount is limited by membrane capacity and compatibility. Excess loading may lead to crystallization or phase separation.

• Structural details: Liposome size typically ranges from tens of nanometers to micrometers. The lipid bilayer thickness is on the nanometer scale (often reported in the literature as roughly ~4–5 nm). Cholesterol, saturated vs. unsaturated chains, chain length, and phase state (gel vs. liquid-crystalline) can all change membrane thickness and packing density.

3) What are typical features of “liposome products”?

• Improved formulation usability: Encapsulate or embed poorly soluble or easily degraded molecules to reduce direct exposure in the system.
• Tunable release and distribution: By adjusting membrane composition, membrane fluidity, particle size, etc., one can tune release rate and distribution tendencies in vivo or within a formulation system.
• Surface modifiability: For example, designs for long-circulating/“stealth”, targeting, immuno-related functions, or stimulus responsiveness.
• Clinically validated delivery modality: Multiple liposomal drug products have been approved and used clinically (e.g., anti-cancer, anti-infective), so liposomes are often considered a relatively “translatable” delivery route in research. At the same time, this means critical quality attributes (CQAs) and scale-up process control are crucial and typically demanding.

4) What are common applications?

• Drug delivery (most typical): Small molecules, proteins/peptides, nucleic acids, imaging probes, etc.
• Vaccines/immuno-delivery and adjuvant systems: Liposomes can serve as a carrier platform for antigens and/or immunomodulators (e.g., the concept behind systems like AS01, where a liposome carrier is combined with immunostimulatory molecules).
• Nucleic acid delivery/transfection (common in cell experiments): Cationic liposomes/lipid complexes are often used to bind negatively charged nucleic acids and facilitate cellular entry.
• Membrane science and model systems: Model membranes for membrane protein studies, membrane phase behavior, drug–membrane interactions, and related “model cell membrane” work.
• Note (common confusion): Many LNPs discussed for mRNA delivery are often not classic bilayer vesicles. Their internal structures tend more toward non-lamellar or mixed/complex lipid–nucleic acid assemblies, and their formulation goals differ accordingly.

5) How to classify liposome products?

Classification dimension	Common categories	What differences you get
Lamellarity / structure	SUV (small unilamellar), LUV (large unilamellar), MLV (multilamellar / “onion-like”), etc.	Affects encapsulation capacity, release, stability, etc.; unilamellar vs. multilamellar can differ greatly
Size	From tens of nm to micrometers	Size influences circulation time, tissue distribution, cellular uptake, etc. (especially in vivo)
Surface charge	Neutral / anionic / cationic	Cationic systems bind nucleic acids and adhere to cells more readily, but often have higher irritation/toxicity risk (more sensitive in vivo)
Formulation generation / functionalization	Conventional liposomes; long-circulating/stealth; targeted; immunoliposomes; stimulus-responsive, etc.	Matches different “missions”: prolonged circulation, reduced clearance, improved targeting/triggered release, etc.

6) A step-by-step selection workflow: “from problem to product”

Step 1: Clarify what you want to deliver/encapsulate

• Hydrophilic small molecules / proteins / antigens → focus more on aqueous-core encapsulation efficiency and leakage rate
• Hydrophobic small molecules → focus more on membrane compatibility and membrane stability
• Nucleic acids (DNA/RNA/siRNA) → in most cases, prioritize cationic liposomes/lipid complex systems

Step 2: Is it an in vitro cell experiment or an in vivo animal/translational direction?

• In vitro: Usually focus on transfection efficiency, cytotoxicity, serum compatibility, and reproducibility
• In vivo: Prioritize particle size/PDI, stability, immunogenicity risk, and whether long circulation is needed (e.g., PEGylation)

Step 3: Choose the “structure and size tier”

• For rapid cell entry and a uniform system → often prefer unilamellar structures with more controllable size (e.g., SUV/LUV)
• For higher loading and/or slower release → sometimes consider MLV (but the system is more complex)
• For hydrophilic payloads: to increase encapsulation, common strategies include increasing internal aqueous volume and optimizing process (e.g., LUV, freeze–thaw, extrusion conditions, concentration gradients, etc.). Because MLVs have more membrane layers occupying volume, the “usable internal aqueous volume per unit lipid mass” is not necessarily higher, but they may provide longer diffusion/release pathways.
• For hydrophobic payloads: the greater “amount of membrane” in MLVs can sometimes increase hydrophobic payload partitioning capacity (still limited by compatibility/phase separation risk).

Step 4: Decide whether you need surface functions (most commonly PEG and/or targeting)

• Need longer circulation / reduced clearance → consider PEGylated/stealth designs; note that repeated dosing may induce ABC (accelerated blood clearance) phenomena (often discussed in animal studies).
• Need cell/tissue specificity → add targeting ligands (but validation cost and complexity are higher)

Step 5: Choose a loading strategy (determines whether you can “load enough” and “keep it stable”)

• Passive loading: Co-encapsulate during preparation; simple workflow but efficiency may be limited
• Active/remote loading (e.g., ion-gradient methods): For some weakly basic amphiphilic drugs, loading efficiency can be very high and more stable (classic example: ammonium sulfate gradient loading for certain anthracyclines, etc.)

Step 6: Write “acceptance criteria” into your SOP

• Particle size and distribution (DLS, PDI), zeta potential
• Encapsulation efficiency/drug loading, free drug fraction
• Release/leakage (under actual medium/serum conditions)
• Sterility/endotoxin
• Residual organic solvents/lipid oxidation indicators (if chloroform/ethanol is used or if unsaturated lipids are included)

7) Quick mapping: common needs → common liposome routes

Task	Common preferred route
Cell transfection (DNA/RNA)	Cationic liposomes/lipid complexes (check toxicity and serum compatibility first)
Hydrophobic small-molecule delivery/solubilization	Focus on membrane compatibility and stability (can further add long-circulating/targeting features)
Improve loading and stability for some weakly basic drugs	Evaluate ion-gradient/remote-loading solutions
Build a more “translatable” drug-delivery model	Start with classic liposome platforms to control size/composition/stability, then upgrade via functionalization

8) Formulation Materials Navigator for Liposomes and Lipid Nanoparticles (LNPs): Phospholipid/Sterol Matrices, Functional Lipids, and Fluorescent Probes (Table 1–Table 3)

Selection Navigator Table

Problem/goal to solve	Which table to check first	Why this table	Typical items you will use
You just want to build a “basic liposome/model membrane” and get the membrane assembled	Table 1	Table 1 provides the chassis of main lipids + helper lipids + charge control, which determines whether the membrane is stable, fluid, and charged	Natural phospholipids/PC sources; synthetic phospholipids—neutral PCs (DOPC/POPC/DMPC/DPPC/DSPC); cholesterol/sterol helper lipids; PE helper lipids (DPPE/DMPE/DOPE); anionic lipids (PS/PG/PA)
You need a more stable/“stiffer” membrane to reduce leakage and improve storage stability	Table 1	The key is selecting high-Tm main lipids plus cholesterol/hydrogenated lipids, etc.	DSPC/DPPC; hydrogenated PC; cholesterol
You need to tune “surface charge” (negative/strongly negative, or model membranes mimicking cell surfaces)	Table 1	Table 1 concentrates anionic lipids such as PS/PG/PA and anionic additives for zeta potential and interaction tuning	DOPS/PS; DOPG/DPPG/DMPG; PA; anionic additive—dicetyl phosphate
For nucleic-acid delivery/transfection (DNA/siRNA/mRNA), you need positive charge or pH responsiveness	Table 2	Delivery performance mainly comes from cationic/ionizable lipids (loading + endosomal escape)	Cationic lipids (DOTAP/DOTMA/quaternary ammonium types); ionizable lipids (MC3, SM-102, ALC-0315)
You need “stealth/long circulation,” reduced aggregation and protein adsorption, or better manufacturability	Table 2	These needs are primarily achieved via PEGylated lipids (steric stabilization; size/dispersity control)	DSPE-PEG (2000/5000); ALC-0159; DMG-PEG2000
You need targeting/conjugation (peptides, antibodies, dyes, ligands)	Table 2	Table 2 provides end-reactive PEG lipids (MAL/NH2/COO⁻) for site-specific or general conjugation	DSPE-PEG-MAL; DSPE-PEG-NH2; DSPE-PEG-COO⁻ (sodium salt)
You want to “see it”: membrane labeling, in vivo/cellular tracking, co-localization imaging	Table 3	Table 3 contains lipophilic membrane probes/fluorophores that insert into the bilayer for imaging and tracking	DiI/DiA/DiD/DiR’/cyanine membrane probes; Rhodamine B
You want to assess “leakage/release”: encapsulation, permeability, leakage assays	Table 3	Table 3 provides hydrophilic encapsulation markers: load into the aqueous core; signal changes upon release to assess leakage/permeability	Calcein; 6-carboxyfluorescein

Table 1 | Base Membrane Materials and Charge-Tuning Lipids (Natural/Synthetic Phospholipids + Sterols/Anionic Lipid Additives)

Category	CAS No.	Aladdin Cat. No.	Name	Specification/Purity	Product features or applications
Natural phospholipids—lecithin/PC source	8030-76-0	L1455894	Lecithin, from soybean	Natural, with 45% phosphatidylcholine	Natural mixed phospholipids (contains a certain PC fraction), commonly used for “natural/food-grade” style liposomes and emulsification systems.
Natural phospholipids—lecithin/PC source	8002-43-5	P1456010	Phospholipids, from sunflower (non-GMO)	Natural, with ≥60% phosphatidylcholine	Higher PC content (≥60%), suitable for neutral liposomes/emulsions; “non-GMO” helps with formulation claims and source control.
Natural phospholipids—high-purity PC	97281-44-2	L130151	L-α-Phosphatidylcholine (egg)	Natural, ≥95%	High-purity PC (neutral main lipid), a classic liposome matrix material for model membranes and baseline formulations.
Natural phospholipids—hydrogenated PC (more rigid)	97281-48-6	P1456034	Hydrogenated phosphatidylcholine, from non-GMO soybean	Natural, ≥90%	More saturated after hydrogenation → higher transition temperature and a “stiffer/more stable” membrane; often used to improve storage stability and reduce leakage.
Cholesterol/sterol helper lipid	57-88-5	C104036	Cholesterol	For cell culture, ≥99% (GC)	A common liposomal “helper lipid” that increases packing and stability, reduces leakage, and modulates membrane fluidity.
Cholesterol derivative—anionic/pH-tunable	1510-21-0	C132483	Cholesteryl hemisuccinate	≥97%	Often used to introduce ionizable/negative characteristics and tune membrane phase behavior; also common in membrane-protein and liposome stabilization studies.
Synthetic phospholipids—neutral PC (main lipid)	4235-95-4	D130438	1,2-Dioleoyl-sn-glycero-3-phosphocholine	Moligand™, ≥99%	DOPC (unsaturated PC): more fluid at room temperature; widely used for general liposomes, model membranes, and membrane-protein reconstitution.
Synthetic phospholipids—neutral PC (main lipid)	26853-31-6	P130452	1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)	≥99%	POPC (16:0/18:1) is among the most widely used “biomembrane-like” model PCs for liposomes and membrane-protein studies.
Synthetic phospholipids—neutral PC (main lipid)	18194-24-6	D130420	Dimyristoyl phosphatidylcholine (DMPC)	≥99%	DMPC (C14) has a relatively low phase transition temperature; commonly used for fluid model membranes, liposomes, and thermal behavior studies near room temperature.
Synthetic phospholipids—neutral PC (main lipid)	63-89-8	D1494308	Dipalmitoyl phosphatidylcholine (DPPC)	Moligand™, 10 mM in ethanol	DPPC (saturated PC) has a high transition temperature and is suited for “stiffer” liposomes and thermo/temperature-sensitive liposome research; the 10 mM ethanol solution is convenient for formulation.
Synthetic phospholipids—neutral PC (main lipid/isomer)	2644-64-6	D353387	1,2-Dipalmitoyl-rac-glycerol-3-phosphocholine	≥95%	A DPPC-type PC (rac form), used for model membrane/liposome formulation studies (similar applications to DPPC).
Synthetic phospholipids—high-Tm neutral PC (main lipid)	816-94-4	D130429	1,2-Distearoyl-sn-glycero-3-phosphocholine (DSPC)	Moligand™, ≥99%	DSPC has a high transition temperature and forms a more rigid membrane; often used in long-circulating/stable liposomes (commonly paired with cholesterol and PEG lipids).
Synthetic phospholipids—neutral PE (helper lipid)	923-61-5	D130469	1,2-Dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE)	Moligand™, ≥99%	DPPE (PE headgroup) tunes membrane curvature/fusion properties and can serve as an anchor lipid for subsequent derivatization.
Synthetic phospholipids—neutral PE (helper lipid)	998-07-2	D130473	1,2-Dimyristoyl-sn-glycero-3-phosphoethanolamine	≥98%	DMPE (PE) tunes curvature/phase behavior; can be combined with PC/cholesterol to adjust stability and fusion characteristics.
Synthetic phospholipids—neutral/fusogenic PE	4004-05-1	D432691	1,2-Dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE)	≥99%, 10 mg phospholipid per ml CHCl₃, TLC	DOPE is a classic “fusogenic/endosomal escape–promoting” helper lipid, often paired with cationic/ionizable lipids to enhance delivery efficiency.
Synthetic phospholipids—anionic PS (negatively charged)	90693-88-2	D130321	1,2-Dioleoyl-sn-glycero-3-phospho-L-serine (sodium salt) (DOPS)	Moligand™, ≥99%	DOPS (PS) provides negative charge and PS-specific interaction features; commonly used to mimic biomembranes and tune liposome surface charge and cell interactions.
Synthetic phospholipids—anionic PS (negatively charged)	70614-14-1	D462978	1,2-Dioleoyl-sn-glycero-3-phospho-L-serine sodium salt	≥95%	Dioleoyl PS (sodium salt) provides negative charge and PS-specific interaction features; used in studies of membrane asymmetry/externalization and phagocytosis-related mechanisms.
Synthetic phospholipids—anionic PG (negatively charged, high-Tm)	200880-42-8	D130352	1,2-Distearoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (sodium salt)	≥97%	DSPG (PG): a high-Tm anionic lipid used to provide a stable negative surface and enhance stability (high compatibility with DSPC-based systems).
Synthetic phospholipids—anionic PG (negatively charged)	67232-81-9	D433257	1,2-Dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt	≥99% (TLC)	DPPG (PG) provides negative charge and improves colloidal stability; often used to tune zeta potential, reduce non-specific binding, or build model membranes.
Synthetic phospholipids—anionic PG (negatively charged)	67254-28-8	D130353	1,2-Dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt	≥99%	DOPG (PG) is a more fluid anionic lipid, used to maintain membrane fluidity while providing a negative surface.
Synthetic phospholipids—anionic PG (negatively charged)	200880-40-6	D130348	1,2-Dimyristoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (DMPG) (sodium salt)	≥99%	DMPG (C14) has shorter chains and a lower transition temperature; suitable for more fluid anionic model membranes/liposome systems.
Synthetic phospholipids—anionic PA (strongly negative)	108392-02-5	D130369	1,2-Dioleoyl-sn-glycero-3-phosphate (sodium salt) (18:1 PA)	≥99%	PA (phosphatidic acid) has a small headgroup and strong negative charge; strongly affects curvature/electrostatics and protein interactions; used in mechanism studies and formulation tuning.
Anionic additive—negative charge/stabilization	2197-63-9	D100915	Dicetyl phosphate	≥90%	A dialkyl phosphate anionic additive that introduces negative charge and can improve dispersion stability/reduce aggregation in liposome systems.

Table 2 | Delivery and Surface-Engineering Lipids (PEGylation + Cationic/Ionizable + Surface Modification)

Category	CAS No.	Aladdin Cat. No.	Name	Specification/Purity	Product features or applications
Synthetic phospholipid—neutral PE (anchor lipid)	1069-79-0	D130471	1,2-Distearoyl-sn-glycero-3-phosphoethanolamine (DSPE)	≥97%	DSPE has high Tm and strong hydrophobic anchoring; a common base anchor for PEGylated/ligand-modified lipids (DSPE-PEG-*).
PEGylated lipid—stealth/long circulation	147867-65-0	D163638	DSPE PEG, mPEG-DSPE MW 5000 Da	5000 Da	DSPE anchor + PEG corona provides steric stabilization and “stealth” effects, reducing aggregation/protein adsorption; widely used for long-circulating liposomes and LNP surface modification.
PEGylated lipid—stealth/long circulation	247925-28-6	M404766	MPEG2000-DSPE sodium salt	MW 2000 Da	PEG2000-DSPE (sodium salt) for size control, dispersion stability, and reduced non-specific adsorption; common in LNP/liposome formulation optimization.
PEGylated lipid—conjugatable (maleimide)	474922-22-0	D163619	DSPE PEG Maleimide, DSPE-PEG-MAL MW 2000 Da	2000 Da	Terminal maleimide enables site-specific conjugation with thiols (-SH) (peptides/antibodies/ligands) for targeted liposome surface functionalization.
PEGylated lipid—conjugatable (amino)	474922-26-4	D163596	DSPE-PEG-NH₂	MW 2000 Da	Terminal -NH₂ supports conjugation with NHS esters/isocyanates, etc., for grafting dyes, drugs, or targeting ligands.
PEGylated lipid—conjugatable (carboxylate)	1403744-37-5	D646435	DSPE-PEG carboxylate sodium salt	MW 2000	Terminal -COO⁻ (sodium salt) can be EDC/NHS-activated to couple amine ligands; can also tune surface charge and colloidal stability.
PEGylated lipid—PEG lipid for LNPs	1849616-42-7	A648398	ALC-0159	Moligand™, ≥98%	A commonly used PEG lipid for mRNA LNPs (critical for size and dispersion stability); reduces aggregation, improves manufacturability and in vivo distribution.
PEGylated lipid—PEG lipid for LNPs	160743-62-4	D773877	DMG-PEG 2000	≥95%	A common PEG lipid for LNPs (often of a more “sheddable/exchangeable” type); used for size control, reduced aggregation, improved dispersion and manufacturability.
Cationic lipid—permanent positive charge (transfection)	132172-61-3	D351073	1,2-Dioleoyl-3-trimethylammonium-propane chloride (DOTAP)	Moligand™, ≥99%	Classic cationic lipid for nucleic-acid complexation and transfection liposomes (often formulated with DOPE).
Cationic lipid—permanent positive charge (transfection; ether linkage)	104872-42-6	D292947	1,2-Dioctadecenyl-3-methylammonium propane chloride (DOTMA)	≥98%	Classic ether-linked cationic lipid (DOTMA) for nucleic-acid complexation/transfection; ether linkage is relatively more hydrolysis-resistant.
Cationic lipid/ether analog—quaternary ammonium	104162-48-3	T162217	Trimethyl[2,3-(dioleyl oxy)propyl]ammonium chloride	≥90%	A quaternary ammonium ether lipid used for nucleic-acid complexation/cationic liposome construction and surface charge tuning.
Cationic lipid/surfactant—quaternary ammonium	3700-67-2	D130818	Didodecyldimethylammonium bromide	≥98%	A DODAB-type double-chain quaternary ammonium that can form bilayer vesicles/cationic liposomes for positive surfaces and nucleic-acid complex studies.
Cationic amine—liposome surface modification	124-30-1	O108436	Octadecylamine	≥97% (GC)	A long-chain primary amine used to build cationic/reactive liposome surfaces (introducing amine sites and tuning charge).
Ionizable lipid—LNP core	2036272-55-4	A419992	ALC-0315	Moligand™, ≥98%	One of the core ionizable lipids used in mRNA LNPs: becomes positively charged under acidic conditions to promote endosomal escape, while being relatively less toxic near neutral pH; used for nucleic-acid delivery formulations.
Ionizable lipid—LNP core	1224606-06-7	D302656	D-Lin-MC3-DMA, cationic lipid	≥98%	A classic ionizable lipid (representative for LNP/siRNA delivery); pH responsiveness benefits endosomal escape and it is often used as the main ionizable lipid in LNP formulations.
Ionizable lipid—LNP core	2089251-47-6	S646450	SM-102	≥98%	A commonly used ionizable lipid for mRNA LNPs, supporting nucleic-acid loading and endosomal escape optimization (often formulated with PEG lipids, cholesterol, DSPC, etc.).

Table 3 | Tracking and Characterization Dyes (Lipophilic Membrane Probes + Hydrophilic Encapsulation Markers + Other Fluorophores)

Category	CAS No.	Aladdin Cat. No.	Name	Specification/Purity	Product features or applications
Fluorescent probe—membrane staining/tracking (lipophilic)	41085-99-8	D131225	1,1′-Dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI)	For fluorescence analysis, ≥98%	A classic lipophilic cyanine dye that inserts into lipid bilayers for liposome/cell-membrane labeling and tracking (orange-red fluorescence; wash-resistant).
Fluorescent probe—membrane staining/tracking (lipophilic)	34215-57-1	D131213	3,3′-Dioctadecyloxacarbocyanine perchlorate	≥98%	A lipophilic cyanine membrane probe that inserts into bilayers, used for fluorescent tracking and imaging of liposomes/cell membranes.
Fluorescent probe—membrane staining/tracking (lipophilic)	114041-00-8	D598344	DiA (green fluorescent cell-membrane probe)	_	A green lipophilic membrane probe that inserts into lipid bilayers for liposome/cell-membrane labeling and tracking.
Fluorescent probe—membrane staining/tracking (lipophilic)	362596-00-7	D598346	DiD (red fluorescent cell-membrane probe)	_	A red/far-red lipophilic membrane probe suitable for long-term liposome/cell-membrane tracking and co-localization imaging.
Fluorescent probe—membrane staining/tracking (lipophilic)	127274-91-3	D266406	DiD perchlorate	≥98%	A far-red/near-IR lipophilic membrane dye suitable for in vivo/cellular liposome tracking (lower background and better tissue penetration).
Fluorescent probe—membrane staining/tracking (near-IR)	100068-60-8	D131031	DiR′ [DiIC18(7)], for membrane staining	≥95%	A near-IR lipophilic membrane dye for small-animal in vivo imaging and liposome biodistribution tracking (better tissue penetration).
Fluorescent dye—label/control	3520-42-1	L109288	Lissamine Rhodamine B	For cell culture, ≥85%	A rhodamine fluorophore used for fluorescence controls, labeling, and imaging (also often combined with lipid/carrier systems for tracking).
Encapsulation marker/leakage assay (hydrophilic dye)	1461-15-0	C432128	Calcein	Metal indicator	A hydrophilic fluorescent dye commonly used to evaluate liposome leakage/permeability after aqueous-core encapsulation (often via self-quenching → dequenching upon release).
Encapsulation marker/leakage assay (hydrophilic dye)	3301-79-9	C105327	6-Carboxyfluorescein	≥95%	A hydrophilic fluorescent tracer commonly used for aqueous-core encapsulation and release/leakage evaluation (can also serve as a pH-related readout).

Note: The above are representative Aladdin products. For more specifications, please refer to the product list at the end of the document or search by product name/CAS on the Aladdin website.

Aladdin: https://www.aladdinsci.com/