الفهرس 
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Abstract
The present study is divided into three parts:
The first part: Preparation of Poly ethylene oxide-Poly acrylic acid (PEO- PAAc) nanogel and Poly ethylene oxide-Poly
acrylic acid/ conjugated with Folic acid (PEO-PAAc)/FA.
99mTc.
The second part: Radiolabeling of PEO-PAAc / FA with
The third part: In vivo biodistribution of 99mTc-PEO- PAAc/FA complex in normal mice after intravenous injection and in solid tumour bearing mice after intravenous and intratumor injection.
Results can be summarized as follow:
The first part: Preparation of Poly ethylene oxide-Poly acrylic acid (PEO- PAAc) nanogel and Poly ethylene oxide-Poly acrylic acid/Folic acid conjugate PEO-PAAc/FA:
1- PEO-PAAc was prepared via gamma radiation induced polymerization and crosslinked network.
2- There are some factors that control the size of the prepared nanogel such as: the polymer feed composition,
irradiation dose and the feed concentration of PEO and
PAAc.
3- The molar ratio 30/70 was the optimum feed composition of the two components, the feed concentration was 1% wt and the optimum irradiation dose was 40kGy.
4- PEO-PAAc was conjugated with Folic acid which acts as a targeting receptor.
5- PEO-PAAc & PEO-PAAc/FA were characterized using
DLS, TEM, AFM, XRD and FT-IR.
6- The particle size of PEO-PAAc & PEO-PAAc/FA was determined using DLS and the hydrodynamic mean diameter was found to be 129 nm and 150 nm for PEO- PAAc and PEO-PAAc/FA respectively.
7- The morphology of PEO-PAAc & PEO-PAAc/FA was carried out by TEM and AFM techniques. TEM images of PEO-PAAc were appeared as a spherical shape with diameter ranged (70-120) nm.
8- The AFM images of PEO-PAAc appeared as a homogenous circular shape. The spherical shape of PEO- PAAc was distorted as the FA was added.
9- The structure of PEO-PAAc & PEO-PAAc/FA was confirmed by XRD and FT-IR.
The second part: Radiolabeling of PEO-PAAc/FA
with 99mTc.
1- PEO-PAAc/FA was radiolabeled with radionuclides as
99mTc where, 99mTcO4- was reduced firstly with a reducing agent as sodium dithionide Na2S2O4 then, the reduced product was added into PEO-PAAc complexing agent.
2- The factors controlling the % radiochemical yield were determined by the amount of the complexing agent, the amount of the reducing agent and the reaction time.
3- The % radiochemical yield was reached to 88% at 5 min reaction time when 350 μL of 99mTc-PEO-PAAc /FA were added to 50 μL Na2S2O4.
4- The particle size and the charge of 99mTc-(PEO-PAAc)
/FA complex were measured by DLS where, the hydrodynamic mean diameter and the charge were found
98 nm and+ 50.31 mV, respectively.
The third part: In-vivo biodistribution of 99mTc-(PEO- PAAc/FA complex in normal mice after intravenous injection and in solid tumor bearing mice after intravenous and intratumor injection.
1- The in-vivo biodistribution of 99mTc-PEO-PAAc/FA
complex was carried out in normal mice after intravenous
injection and in solid tumor bearing mice after intravenous and intratumor injection.
2- The biodistribution in normal mice after intravenous injection showed no accumulation in specific body organ and excretion was via renal and hepatobiliary pathways.
3- Kidneys showed uptake of 55.896 % ID/g at 60 min while liver showed 19.855 %ID/g at 5 min post injection.
4- The biodistribution after I.V. injection in solid tumor bearing mice, cancer muscle showed higher uptake than normal muscle at 30 min post injection (9.065 and 1.466
%ID/g, respectively). Such uptake indicated the selectivity of 99mTc-PEO-PAAc/Folic acid to the cancerous tissue.
5- The T/NT ratio was 1.673 at 5 min post injection and increased to the highest value 6.186 at 30 min post injection.
6- Intra-tumor injection in solid tumor bearing mice showed uptake of 55.27 %ID/g in cancerous muscle and 0.850
%ID/g in normal muscle at 5 min with T/NT ratio of 85.
7- The obtained results show the high selectivity and retention properties of 99mTc-PEO-PAAc/Folic acid in tumor tissue.