ISSAC NEWTON

i am interested in discussing about the pros and cons of having a vesicle of ph sensitive polymer (with drug to be delivered inside it), inside a vesicle of thermosensitive polymer for drug delivery. This gives us dual control capabilities that is temperature and ph based trigger mechanism.things i need to know about this are 1. is this method a novel approach for drug delivery, for a disease which needs a local site and ph change for drug release. 2. the ph sensitive polymer works based on feedback approach like the release of drug is based on ph change in the system.external triggering is involved for temperature change. 3. what are the difficulties in design of such drug delivery approach. 4. can i use this method specifically for some disease preferably(like some particular cancer demanding temperature and ph conditions) ? thank you all.

THANK YOU FOR YOUR REPLY.NOW TELL ME WILL THERE BE A PHASE SHIFT IN THE INPUT SINE WAVE IN A LOW AND HIGH PASS FILTER WHEN THE GAIN=1?I GOT NO PHASE SHIFT WHEN I SIMULATED IT(@ GAIN=1).IF NO SHIFT,WHY? I WOULD LIKE TO KNOW THE REASON BEHIND IT.PHYSICAL INTERPRETATIONS ARE WELCOME RATHER THAN MATHEMATICAL REASONING.THANK YOU.

what happens to the phase of a sine wave when passed through a high pass filter circuit and a low pass filter circuit.does capacitor always produce a 90 degree phase shift for a sine wave at all frequencies.please tell me the response at different frequencies of signals.can we see the phase shift produced by an inductor to current in a cro , or only voltages can be seen in it? please comprehend.