Firstly, I would like to welcome all the readers, authors, editorial team and management of Pakistan Biomedical Journal (PBMJ) to this new journal in Biomedical Sciences. It is an intenational peer-reviewed, open-access journal that merges the basic and clinical research for the better outcome in terms of diagnosis and therapeutics. This approach will update and upgrade the existing knowledge among the researchers and clinicians, regarding the patient care and practice as well as understanding of underlying mechanisms of diseases. The ultimate beneficiary is patient and community as a whole. PBMJ is led by an outstanding Editorial Board comprising of national and international members with multidisciplinary research background. Our goal is to promote the basic and clinical research, health and disease perspectives. We receive original studies, review articles, case reports, systemetic reviews on medical, biomedical, basic and therapeutic research. We welcome scientific contributions from all over the world. It is the need and demand of the recent world scenario to focus on biomedical research. In the current world, basic and medical science cannot be considered as two separate and independent entities. There should be coherent efforts to unveil the basic understandings of pathologies at physiological, cellular and molecular level. Furthermore, the therapeutic strategies should also be explored on regional and global levels, by keeping in mind the different genetic makeups and considering the individual identities. It leads to the field of ‘personalized medicine’. There are many other recent therapeutic regimens such as regenerative medicine, exosomes, gene silencing and gene editing technologies. The world has also advanced in diagnostic modalities. Much focus has been emphasized on rapidness, accuracy and cost-effectiveness of these techniques. Imaging, scanning, histopathological, biochemical and hematological techniques have been much advanced than before. World has been changing rapidly in medical profession. Hence, it is important to be aware of these advancements worldwide and also to share the health related researches at local level. We hope this new journal will be a good addition in this perspective of sharing the recent knowledge, advancements and create awareness among masses.
The technetium ( 99m Tc) radiopharmaceuticals have been used for diagnosis of many diseases especially cancer in nuclear medicine for many years ago. Currently, target specific radiopharmaceuticals containing peptides have become more interesting due to increasing the knowledge of receptor binding affinity of specific peptides as well as ease of chemical modification of peptide sequences. Many chelators have been developed as bifunctional chelators for 99m conjugation to peptides as well as for chelation with Tc. Small size chelators are desireable for labeling the small peptides. One of the most important requirements of radiopharmaceuticals is an aqueous phase labeling the biomolecules to 99m Tc. These requirements must meet in order to use for nuclear medicine. In this context, cyclopentadiene (Cp - ) is obviously as a good choice of chelator due to its small size and low molecular weight. The 99m Tc radiolabeled peptide comprising Cp - core have not been synthesized in an aqueous phase. Instead, they have been synthesized by double ligand transfer approach in an organic solvent using harsh reaction conditions which are still not suitable for routing use. In this study we describe the syntheses of half-sandwich complexes of the type [h 5 -Cp(CONH-R)M(CO) 3 ] with M=Re or 99m Tc. The R group represents different tri-peptides which display high binding affinities for oligopeptide transporters PEPT2 and cyclic RGD peptides which have high binding affinity with integrin family receptor. The 99m Tc complexes [(h 5 - CpCONH-R) 99m Tc(CO) 3 ] were prepared directly from [ 99m Tc(OH 2 ) 3 (CO) 3 ] + and Diels-Alder dimerized, cyclopentadienyl derivatized peptides in an aqueous phase. This approach corroborates the feasibility of metal-mediated retro- Diels-Alder reactions for the preparation of not only small molecules but also of peptides for carrying a [(h 5 -Cp) 99m Tc(CO) 3 ] tag. The Diel-Alder products [(HCpCONH-R) 2 ] containing selected peptides were synthesized from Thiele’s acid [(HCp-COOH) 2 ] via double peptide coupling. The peptides of different sequences in this study were prepared through solid phase peptide synthesisxiv (SPPS). The Re-complexes [(h 5 -CpCONH-R)Re(CO) 3 ] were synthesized by attaching [(Cp-COOH)Re(CO) 3 ] directly to the N-terminus amino group of peptides as prepared from SPPS. The authenticity of the 99m Tc-complexes is confirmed by HPLC retention time comparison with the corresponding rhenium complexes, fully characterized by spectroscopic techniques.