Related Experiment Video
Updated: Feb 1, 2026
06:40
Biofunctionalization of Magnetic Nanomaterials
Published on: July 16, 2020
3.0K
Membrane reorganization after photochemical internalization to release transferrin-biofunctionalized polystyrene
Inmaculada Mora-Espí1, Lleonard Barrios1, Elena Ibáñez1
1Unitat de Biologia Cel·lular, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Spain.
Scientific Reports
|December 6, 2018
Summary
Photochemical internalization (PCI) disrupts endolysosomal membranes, allowing soluble drug release. However, PCI does not fully release microparticles from the endolysosome to the cytosol.
Area of Science:
- Cell Biology
- Nanotechnology
- Drug Delivery
Background:
- Therapeutic drug carriers face challenges releasing cargo from endolysosomes.
- Photochemical internalization (PCI) is a proposed method to overcome endolysosomal entrapment.
- The extent of PCI-induced membrane disruption and microparticle release remains unclear.
Purpose of the Study:
- To investigate if PCI facilitates microparticle release from endolysosomes to the cytosol.
- To analyze the ultrastructural effects of PCI on endolysosomal membranes surrounding microparticles.
Main Methods:
- Confocal microscopy to assess membrane disruption and cargo release.
- Transmission electron microscopy (TEM) for ultrastructural analysis.
- Scanning TEM with energy-dispersive X-ray for membrane characterization.
Main Results:
- PCI caused endolysosomal membrane disruption, evidenced by soluble transferrin release.
- Co-localization of LAMP1 and microparticles decreased post-PCI.
- TEM revealed fewer defined membranes around microparticles after PCI.
- Increased endolysosomal membrane width was observed after PCI treatment.
Conclusions:
- PCI alters endolysosomal membrane ultrastructure.
- This alteration is sufficient for soluble cargo release but not complete microparticle liberation.
Related Concept Videos
01:28The Early Endosome: Endocytosis of Transferrin
4.8K
Essential proteins such as insulin or low-density lipoprotein (LDL) and micronutrients such as iron enter a eukaryotic cell through receptor-mediated endocytosis. Subsequently, the early endosomes fuse with the vesicles containing such receptor-ligand complexes and play a vital role in sorting the incoming ligands and receptors. While the ligands are either degraded inside the vesicle or released into the cytosol, their receptors are returned to the plasma membrane for further rounds of...
4.8K
01:31Internal Receptors
74.7K
Many cellular signals are hydrophilic and therefore cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross the hydrophobic core of the plasma membrane and bind to internal, or intracellular, receptors that reside within the cell. Many mammalian steroid hormones use this mechanism of cell signaling, as does nitric oxide (NO) gas.
74.7K
02:00Internal Energy
36.8K
The total of all possible kinds of energy present in a substance is called the internal energy (U), sometimes symbolized as E. Suppose a system with initial internal energy, Uinitial, undergoes a change in energy (transfer of work or heat), and the final internal energy of the system is Ufinal. Change in internal energy equals the difference between Ufinal and Uinitial.
36.8K
01:29Internal Energy
7.0K
The internal energy of a thermodynamic system is the sum of the kinetic and potential energies of all the molecules or entities in the system. The kinetic energy of an individual molecule includes contributions due to its rotation and vibration, as well as its translational energy. The potential energy is associated only with the interactions between one molecule and the other molecules of the system. Neither the system's location nor its motion is of any consequence as far as the internal...
7.0K
01:29The Photochemical Reaction Center
5.6K
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
5.6K
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.3K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
2.3K