After a brief introduction to Cosmology some quantum aspects of General Relativity and cosmology are presented. The radial motion of a massive particles in the ergosphere of the Kerr Black Hole is considered. Screening of Hawking radiation and shielding of the Penrose process is examined in the context of the region of negative energy inside the ergosphere. Tunnelling of such particles between the boundaries of the classically forbidden region will be considered and the transmission coefficient determined. The evolution of Primordial black holes in standard and Loop Quantum Cosmology is reviewed. A stability analysis of Einstein’s universe in both classical General Relativity and semiclassical Loop Quantum Cosmology regimes is presented. The stability properties of the General Relativity model are significantly altered due to Loop Quantum Gravity corrections. Comparisons between both dynamical systems are considered on the basis of these modifications. The Loop Quantum Cosmology solutions are restricted to an open universe model (k = -1) and represent a cyclic universe. The integrals of motion for both systems are found and their Hamiltonian structure determined.