Formulation, characterization, and evaluation of ligand-conjugated biodegradable quercetin nanoparticles for active targeting

Figures & data

Figure 1. Showing the particle size and zeta potential of ligand-conjugated Qu-NPs. (A) Particle size and Zeta potential of FA-Qu-PLGA nanoparticles. (B) Particle size and Zeta potential of MA-Qu-PLGA nanoparticles.

Figure 3. (A) Three-dimensional (3D) reponse surface plots showing the effect of the variable on the response (Zeta Potential-FA-Qu-PLGA) nanoparticle. (B) Three-dimensional (3D) response surface plots showing the effect of the variable on the response (Zeta Potential-Ma- Qu-PLGA).

Table I. Summarizes the physiochemical characteristics of the prepared nanoformulation, before and after incorporation of FA and MA.

PD ratio (w/w)	Entrapment efficiency (%)	Particle size (nm)	PDI	Zeta potential (mV)
Plain Qu-PLGA NP	57.6 ± 4.2	120.4 ± 10.5	0.208 ± 0.23	− 20.98 ± 2.2
FA-Qu-PLGA NP	71.48 ± 3.2	100.3 ± 7.32	0.287 ± 0.19	− 23.20 ± 3.5
MA-Qu-PLGA NP	75.89 ± 3.20	102.39 ± 7.64	0.324 ± 0.16	− 28.43 ± 1.65

Each batch was prepared by homogenous nanoprecipitation method.

S.E.M: Standard error of Mean; PDI: Polydispersity Index.

Table II. Solubility profile of quercetin (Qu) and its nanoformulations in different solvents.

		Type of formulation
		Free Qu	Qu-NP	FA-Qu-NP	MA-Qu-NP
S.No	Solvents	Solubility
1	Distilled water	Insoluble	Dispersible	Dispersible	Dispersible
2	Ethanol	Soluble	Soluble	Soluble	Soluble
3	Methanol	Sparingly Soluble	Soluble	Soluble	Soluble
4	Acetone	Soluble	Soluble	Soluble	Soluble
5	Ether	Soluble	Soluble	Soluble	Soluble

Table III. Independent variables and their corresponding levels of Qu-PLGA NP preparation for FA binding.

Independent variables	Name	Low level (− 1.00)	Level (0.000)	High level (1.00)
A	Drug/polymer ratio	1/2	1/3	1/5
B	Sonication time	15 min	25 min	35 min
C	Volume of conjugating agents	2/3.5	4/5.5	6.7.5
D	Concentration of ligand	10 μg	30 μg	50 μg

Table IV. Independent variables and their corresponding levels of Qu-PLGA NP preparation for MA binding.

Independent Variables	Name	Low Level (−1)	Level(0)	High Level (1)
A	Drug/Polymer ratio	1/2	1/3	1/5
B	Sonication time	15 min	25 min	35 min
C	Concentration of ligand	20 μg	40 μg	60 μg

Table V. Predicted optimum ranges of the independent variables (MA-Qu-PLGA).

Response	Predicted value	Experimental value	Percent error
Particle size	110.992	102.39	7.75 nm
Zeta potential	− 29.49	28.43	3.59 mV
EE	72.2778	75.89	− 5.008%
Amount of ligand	15.2	20.69	4.83 μM

Percent Error was calculated as (predicted value-observed value)/predicted value × 100%.

Table VI. Predicted optimum ranges of the independent variables (FA-Qu-PLGA).

Response	Predicted Value	Experimental value	Percent error
Particle size	115	100.3	12.78
Zeta potential	25.3	23.20	8.30
EE	75.66	71.58	5.39
Amount of ligand	15	11.46	23.6

Figure 4. In vitro drug release of Qu from ligand-conjugated NPs at a pH of 5.6 and 5.5. (A) The release profile of FA-Qu-PLGA &MA-Qu-PLGA NPs at a pH of 5.6, (B) The release profile of FA-Qu-PLGA &MA-Qu-PLGA-NPs at a pH of 5.5.

Figure 5. Decrease in OD550 shown on increasing concentration of FA-Qu-NP, MA-Qu-NP, Qu-NP, and free Qu, in both cell lines.