Cholesterol removal from various samples by cholesterol-imprinted monosize microsphere-embedded cryogels

Figures & data

Figure 1. Synthesis of MAT monomer.

Figure 2. FTIR spectrum of cholesterol, MAT monomer and cholesterol–MAT monomer complex.

Figure 3. FTIR spectrum of PGMAT microspheres and PGMAT/PHEMA cryogel composite system.

Table I. Swelling properties of the mip/nipPGMAT/PHEMA composite cryogels.

Polymer	Yield (%)	Swelling Ratio (%)	Macroporosity (%)	Linear flow resistance (cm/h)
mipPGMAT/PHEMA	90.4	86	75.3	612
nipPGMAT/PHEMA	91.5	84.2	73.3	624
PHEMA	97.5	96	84	840

Figure 4. SEM images of PHEMA cryogels (A, B); PGMAT/PHEMA composite cryogels, (C, D) (macropore radius: ˜100 μm); Cholesterol-imprinted microspheres (E, F) (microsphere radius: ˜2 μm).

Figure 5. The chromatogram of cholesterol released from the mipPGMAT/PHEMA composite cryogel.

Table II. Statistical evaluation of the calibration data of cholesterol.

Sample	Linearity range (mg/mL)	Slope	Intercept	S.E. of slope	S.E. of intercept	Correlation Coefficient	Detection limit (mg/mL)	Quantitation limit (mg/mL)
Cholesterol	0.2–5	195.6	4.12	0.77	1.89	0.999	0.0509	0.169

Figure 6. Effect of flow rate on cholesterol adsorption. Cholesterol concentration: 0.5 mg/mL, T: 20°C, Time: 2 h.

Figure 7. Effect of initial concentration of cholesterol on adsorption amount. Flow rate: 0.5 mg/mL, T: 20°C, Time: 2 h.

Table III. The Langmuir and Freundlich adsorption isotherm constants.

Exp.	Langmuir constants			Freundlich constants
qex (mg/g)	qmax (mg/g)	b (ml/mg)	R^2	Kf	n	R^2
42.7	75.18	0.18	0.9678	18.3	0.9437	0.9061

Table IV. The pseudo first/second order kinetic constants for mipPGMAT/PHEMA composite cryogel.

Initial Concentration	Experimental	First-order kinetic			Second-order kinetic
(ppm)	qeq (mg/g)	k1 (1/min)	qeq (mg/g)	R^2	k2 (1/min)	qeq (mg/g)	R^2
1.5	32.4	0.066	39.8	0.9122	0.0018	30.08	0.9727

Figure 8. Molecular structures of the competitor molecules.

Figure 9. Adsorption of cholesterol in the presence of competitor estradiol and stigmasterol molecules on mip/nipPGMAT/PHEMA composite cryogels.

Table V. k, k_d and k’ values of estradiol and stigmasterol with respect to cholesterol.

	Polymer
	nipPGMAT/PHEMA		mipPGMAT/PHEMA
Molecule	kd	k	kd	k	k’
Cholesterol	3.01		343.3
Estradiol	22.7	0.13	14.26	24.07	181.6
Stigmasterol	59.01	0.05	39.57	8.6	169.93

Table VI. Cholesterol removal from homogenized cow milk.

Sample	Reference value of cholesterol concentration in milk sample (Han et al. 2005), mg/100 g	Cholesterol concentration in milk sample, g/100 g	Removal, %
Cow milk	13.4	12.3	80

Figure 10. Reusability of mipPGMAT/PHEMA composite cryogel.

Han EM, Kim SH, Ahn J, Kwak HS. 2005. Cholesterol removal from homogenized milk with crosslinked β-cyclodextrin by adipic acid. Asian-Aust J Anim Sci. 18:1794–1799.

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