JULIANNA PRICE &

MENTOR DR. AMY XU
OVERVIEW

What is Insulin? 

What does it do?

Research Methods Results Future Research
INSULIN

 Naturally-secreted peptide 

hormone

 Insulin hexamers are the 

storage form in the system

 Used for the treatment of 

diabetes mellitus types 1 and 2
MODES OF ADMINISTRATION

Current

 Insulin Pen

 Continuous subcutaneous insulin infusion

 Vial and Syringe

Future

 Inhalation

 Nasal

 Oral
MATERIALS

• Use natural 

biomacromolecules as 

materials to make the 

nanoparticles

• Biomacromolecules are 

advantageous because 

they have higher 

biocompatibility as well 

as biodegradability 

Zein Protein – pH(I) 6.8 Pectin Polysaccharide – pKa 3.5

Alginate Polysaccharide – Pka 3.4/4.4 Chitosan Polysaccharide - 6.5
METHOD 1

 Dissolving Ins into HCL and adjusting pH to 8.

 Mix Ins into CaCl2 and Alginate (pH 5.1) in 

different ratios utilizing the sonicator

 Mix previous solution into Chitosan solution (pH 

~5.6) and sonicate

Adapted from Chen et al. 2018
ENCAPSULATION 

EFFICIENCY 

METHOD 1

Beer's Law

Absorbance=εLc

Extinction coefficient

Pathlength

Concentration


METHOD 2

Zein

Adapted from Zhu et al 2019
PARAMETER OPTIMIZATION (METHOD 2)

Sample 1 2 3 4 5 6 7 8 9 10 11 12 13

Content 

(all inc. Ins)

Zn/ 

Buffer

Zn/2 

Pectin

Zn/ 1

0 

Pec.

Zn/

.25 

Alg.

Zn/ 

.75 

Alg

Zn/Ze

Buffer

Zn/Ze/ 

2 Pectin

Zn/Ze 

10 pec

Zn/Ze/ 

.25 Alg

Zn/Ze/ 

.75 Alg

.75 

Alg

Buff. 10 

Pec.

Transmitta

nce %

( λ 630)

100 80.5 81.6 66.4 69.0 39.8 33.3 11.4 12.2 9.2 80.7 100 84.2

• Increased turbidity/Decreased Transmittance = Increased 

nanoparticle formation

• Zein, Zn and a polysaccharide are important factors to 

increased nanoparticle formation/stabilization

• Determination that 2/10mg Pectin and .25/.75mg Alginate 

are best test samples
Lane 1 2 3 4 5 6 8 9 10 11 12

Encapsula

tion 

efficiency

(%)

0 86.32 89.45 81.20 77.62 10.49 87.71 87.14 94.78 95.69 Defragmentation of 

Insulin

Sample Insulin+Z

n into Buf

fer as Co

ntrol

Insulin+Z

n into 2

mg/ml 

Pectin

Insulin+Z

n into 10

mg/ml 

Pectin

Insulin+Z

n into 0.2

5mg/mlA

lginate

Insulin+Z

n into 0.7

5mg/mlA

lginate

Insulin+Z

n+Zein i

nto 

Buffer

Insulin+Z

n+Zein in

to 

2mg/ml P

ectin

Insulin+

Zn+Zein

into 

10mg/ml

Pectin

Insulin+Z

n+Zein i

nto 

0.25mg/

ml Algina

te

Insulin+Z

n+Zein i

nto 0.75

mg/mlAl

ginate

Defragmentation of 

Insulin antisolvent int

o Buffer

• A lack of Zinc leads to the 

defragmentation of Insulin

Multiple bands indicating 

defragmentation

Less intense bands 

indicating higher 

encapsulation efficiency 

rates

More intense bands 

indicating a low insulin 

encapsulation rate
ENCAPSULATION 

EFFICIENCY 
Coating 

Polysaccharide

Insulin:Zn

1:3

Insulin:Zn

1:9

2 mg/mL Pectin 178.8 126.3

10 mg/mL Pectin 130.9 73.5

0.25 Alginate 209.3 207.8

0.75 Alginate 174.5 161.7

Method 2 SANS Results

Model: Guinier Porod

SANS Analysis

•Particles with various Rg are formed

•Smaller particles are formed with increasing 

amount of polysaccharide as well as increasing 

Insulin to Zinc ratio
Stomach pH ~1.2

Intestine pH ~ 6.8

Conclusions: parameters need to be 

tuned so that targeted release can be 

achieved. 

Perhaps coat the nanoparticle with 

multiple layers of polysaccharide so that 

gel matrix is formed, which,

from previous study to be beneficial in 

sustained release of insulin.

Method 2 release results

Zein 20 kDa

Insulin

5.8 kDa
CONCLUSIONS & FUTURE STUDIES

 CaCl2 aided in the formation of insulin hexomers 

(M1)

 A lower concentration of CaCl2 provided a better 

insulin release system (M1)

 A higher concentration of polysaccaride provided 

better nanoparticle formation (M2)

 Zinc is important to avoid insulin degradation as 

well as nanoparticle formation (M2)

 Zein caused insulin degradation in the digestive 

system release

 Further optimization of method 2 nanoparticle 

formation to improve polysaccharide 

concentrations/insulin release in digestive system

 In-vitro nanoparticle release
ACKNOWLEDGEMENTS

 Dr. Amy Xu 

 Dr. Yimin

 Shark Tank & all of NCNR SURFERS