Instruct: Given a question, retrieve passages that answer the question.
Query: Can we make artificial cells?
On December 29, 2011, chemists at Harvard University reported the creation of an artificial cell membrane.[13][14][15]
"The fact that brain processes cause consciousness does not imply that only brains can be conscious. The brain is a biological machine, and we might build an artificial machine that was conscious; just as the heart is a machine, and we have built artificial hearts. Because we do not know exactly how the brain does it we are not yet in a position to know how to do it artificially." (Biological Naturalism, 2004)
Neuron allows for the generation of mixed models, populated with both artificial cells and neurons. Artificial cells essentially function as point processes, implemented into the network. Artificial cells require only a point process, with defined parameters. The user can create the structure and dynamics of network cells. The user can create synapses, using simulated synapse point processes as archetypes. Parameters on these point processes can be manipulated to simulate both inhibitory and excitatory responses. Synapses can be placed on specific segments of the constructed cell, wherein, again, they will behave as point processes, except that they are sensitive to the activity of a pre-synaptic element. Cells can be managed. The user creates the basic grid of network cells, taking previously completed network cells as archetypes. Connections can be defined between source cells and target synapses on other cells. The cell containing the target synapse becomes the post-synaptic element, whereas the source cells function as pre-synaptic elements. Weights can be added to define strength of activation of a synapse by the pre-synaptic cell. A plot option can be activated to open a graph of spikes across time for individual neurons.
The first enzyme studied under artificial cell encapsulation was asparaginase for the treatment of lymphosarcoma in mice. This treatment delayed the onset and growth of the tumor.[23] These initial findings led to further research in the use of artificial cells for enzyme delivery in tyrosine dependent melanomas.[24] These tumors have a higher dependency on tyrosine than normal cells for growth, and research has shown that lowering systemic levels of tyrosine in mice can inhibit growth of melanomas.[25] The use of artificial cells in the delivery of tyrosinase; and enzyme that digests tyrosine, allows for better enzyme stability and is shown effective in the removal of tyrosine without the severe side-effects associated with tyrosine depravation in the diet.[26]
In somatic cell nuclear transfer ("SCNT"), the nucleus of a somatic cell is taken from a donor and transplanted into a host egg cell, which had its own genetic material removed previously, making it an enucleated egg. After the donor somatic cell genetic material is transferred into the host oocyte with a micropipette, the somatic cell genetic material is fused with the egg using an electric current. Once the two cells have fused, the new cell can be permitted to grow in a surrogate or artificially.[18] This is the process that was used to successfully clone Dolly the sheep (see section on History in this article).[3]
Artificial competence can be induced in laboratory procedures that involve making the cell passively permeable to DNA by exposing it to conditions that do not normally occur in nature. Typically the cells are incubated in a solution containing divalent cations (often calcium chloride) under cold conditions, before being exposed to a heat pulse (heat shock). Calcium chloride partially disrupts the cell membrane, which allows the recombinant DNA enter the host cell. Cells that are able to take up the DNA are called competent cells. 
Artificial cells used for drug delivery differ from other artificial cells since their contents are intended to diffuse out of the membrane, or be engulfed and digested by a host target cell. Often used are submicron, lipid membrane artificial cells that may be referred to as nanocapsules, nanoparticles, polymersomes, or other variations of the term.
In March 2015, Church and his genetics research team at Harvard successfully copied woolly mammoth genes into the genome of an Asian elephant. Using the CRISPR DNA editing technique, his group spliced genetic segments from frozen mammoth specimens, including genes from the ears, subcutaneous fat, and hair attributes, into the DNA of skin cells from a modern elephant. This marked the first time that woolly mammoth genes had been functionally active since the species became extinct. Their work has not been subject to peer review, however. Church stated that "Just making a DNA change isn't that meaningful. We want to read out the phenotypes." To do that, the team plans to perform further tests to get the hybrid cells into becoming specialized tissues, and from there attempting to turn the hybrid elephant/mammoth skin cells into hybrid embryos that can be grown in artificial wombs.
Assume inductively that "f" is cellular on the ("n" − 1)-skeleton of "X", and let "e" be an "n"-cell of "X". The closure of "e" is compact in "X", being the image of the characteristic map of the cell, and hence the image of the closure of "e" under "f" is also compact in "Y". Then it is a general result of CW-complexes that any compact subspace of a CW-complex meets (that is, intersects non-trivially) only finitely many cells of the complex. Thus "f"("e") meets at most finitely many cells of "Y", so we can take formula_2 to be a cell of highest dimension meeting "f"("e"). If formula_3, the map "f" is already cellular on "e", since in this case only cells of the "n"-skeleton of "Y" meets "f"("e"), so we may assume that "k" > "n". It is then a technical, non-trivial result (see Hatcher) that the restriction of "f" to formula_4 can be homotoped relative to "X" to a map missing a point "p" ∈ "e". Since "Y" − {"p"} deformation retracts onto the subspace "Y"-"e", we can further homotope the restriction of "f" to formula_4 to a map, say, "g", with the property that "g"("e") misses the cell "e" of "Y", still relative to "X". Since "f"("e") met only finitely many cells of "Y" to begin with, we can repeat this process finitely many times to make formula_6 miss all cells of "Y" of dimension larger than "n".
In the area of synthetic biology, a "living" artificial cell has been defined as a completely synthetically made cell that can capture energy, maintain ion gradients, contain macromolecules as well as store information and have the ability to mutate.[4] Such a cell is not technically feasible yet, but a variation of an artificial cell has been created in which a completely synthetic genome was introduced to genomically emptied host cells.[5] Although not completely artificial because the cytoplasmic components as well as the membrane from the host cell are kept, the engineered cell is under control of a synthetic genome and is able to replicate.
Artificial Cells, Blood Substitutes, and Biotechnology is an academic journal that publishes review articles on the development of artificial cells, tissue engineering, artificial organs, blood substitutes, cell therapy, gene and drug delivery systems, bioencapsulation nanosensors, nanodevices and other areas of biotechnology. It is published by Informa Healthcare.Thomas M.S. Chang, O.C., M.D., C.M., Ph.D., FRCP(C), FRS(C) is the Editor-in-Chief of "Artificial Cells, 
DNA replication (DNA amplification) can also be performed "in vitro" (artificially, outside a cell). DNA polymerases isolated from cells and artificial DNA primers can be used to initiate DNA synthesis at known sequences in a template DNA molecule. Polymerase chain reaction (PCR), ligase chain reaction (LCR), and transcription-mediated amplification (TMA) are examples.
An artificial cell or minimal cell is an engineered particle that mimics one or many functions of a biological cell. The term does not refer to a specific physical entity, but rather to the idea that certain functions or structures of biological cells can be replaced or supplemented with a synthetic entity. Often, artificial cells are biological or polymeric membranes which enclose biologically active materials. As such, nanoparticles, liposomes, polymersomes, microcapsules and a number of other particles have qualified as artificial cells. Micro-encapsulation allows for metabolism within the membrane, exchange of small molecules and prevention of passage of large substances across it.[1][2] The main advantages of encapsulation include improved mimicry in the body, increased solubility of the cargo and decreased immune responses. Notably, artificial cells have been clinically successful in hemoperfusion.[3]
This, Cohn said, suggested "that the suppressor cells produce a factor which, in effect, turns off the macrophage. Or else, the macrophages don't work because of the absence of helper cells. The question is, Can you suppress the suppressors or help the helpers? Some experiments we've been doing in the lab with cells of other diseases indicate that either or both may be possible, but we need to know a lot more about the bacteria and the immune cells before we can manipulate them clinically...What we can learn about these suppressor cells...is also of great interest because there's a fair amount of evidence in many animal models that suppressor cells modify the ability of a host to fight off tumors, and that if you can destroy the suppressor cells, you'll allow normal body defenses to come back and destroy the tumor."
In hemoperfusion, the blood perfuses a filter composed of artificial cells filled with activated carbon or another microporous material. Small molecules in solution within the serum (such as the toxin) cross the membranes into the microporous material (and get trapped therein), but formed elements (the blood cells) brush past the artificial cells just as they brush past each other. In this way, the microporous material's filtering ability can be used without destroying the blood cells.
Artificial cell hemoperfusion has been proposed as a less costly and more efficient detoxifying option than hemodialysis,[1] in which blood filtering takes place only through size separation by a physical membrane. In hemoperfusion, thousands of adsorbent artificial cells are retained inside a small container through the use of two screens on either end through which patient blood perfuses. As the blood circulates, toxins or drugs diffuse into the cells and are retained by the absorbing material. The membranes of artificial cells are much thinner those used in dialysis and their small size means that they have a high membrane surface area. This means that a portion of cell can have a theoretical mass transfer that is a hundredfold higher than that of a whole artificial kidney machine.[1] The device has been established as a routine clinical method for patients treated for accidental or suicidal poisoning but has also been introduced as therapy in liver failure and kidney failure by carrying out part of the function of these organs.[1] Artificial cell hemoperfusion has also been proposed for use in immunoadsorption through which antibodies can be removed from the body by attaching an immunoadsorbing material such as albumin on the surface of the artificial cells. This principle has been used to remove blood group antibodies from plasma for bone marrow transplantation[36] and for the treatment of hypercholesterolemia through monoclonal antibodies to remove low-density lipoproteins.[37] Hemoperfusion is especially useful in countries with a weak hemodialysis manufacturing industry as the devices tend to be cheaper there and used in kidney failure patients.
It is currently an unsolved problem in Artificial General Intelligence and is a focus of the Paul Allen Institute for Artificial Intelligence. Commonsense knowledge can underpin a commonsense reasoning process, to attempt inferences such as "You might bake a cake because you want people to eat the cake." A natural language processing process can be attached to the commonsense knowledge base to allow the knowledge base to attempt to answer commonsense questions about the world. Common sense knowledge also helps to solve problems in the face of incomplete information. Using widely held beliefs about everyday objects, or common sense knowledge, AI systems make common sense assumptions or default assumptions about the unknown similar to the way people do. In an AI system or in English, this is expressed as 'Normally P holds', 'Usually P' or 'Typically P so Assume P'. For example if we know the fact 'Tweety is a bird' , because we know the commonly held belief about birds, 'typically birds fly,' without knowing anything else about tweety, we may reasonably assume the fact that 'Tweety can fly.' As more knowledge of the world is discovered or learned over time, the AI system can revise its assumptions about Tweety using a truth maintenance process. If we later learn that 'Tweety is a penguin' then truth maintenance revises this assumption because we also know 'penguins do not fly'. 
Vectors are propagated most commonly in bacterial cells, but if using a YAC (Yeast Artificial Chromosome) then yeast cells may be used. Vectors could also be propagated in viruses, but this can be time consuming and tedious. However, the high transfection efficiency achieved by using viruses (often phages) makes them useful for packaging the vector (with the ligated insert) and then introducing them into the bacterial (or yeast) cell. 
Later artificial cells have ranged from hundred-micrometer to nanometer dimensions and can carry microorganisms, vaccines, genes, drugs, hormones and peptides.[1] The first clinical use of artificial cells was in hemoperfusion by the encapsulation of activated charcoal.[7]
Nowadays, there are several treatments (still in experimentation) related with stem cell therapy. It is a new opportunity, not only for partners with lack of gamets, but also for homosexuals and single people who wants to have offspring. Theoretically, with this therapy, we can get artificial gamets "in vitro". There are different studies, for both women and men.Stem cell therapy is really new, and everything is still under investigation. However, it could be the future for the treatment of multiple diseases, including infertility. It will take time until these studies can be available for clinics and patients as a regularity.
Feeding normally occurs via stylet penetration of epidermal cells, but sometimes nematodes can enter through stomatal openings and feed from within the mesophyll cell layer. A study showed that "Aphalenchoides fragariae" is more attracted to CO than oxygen emissions in a controlled environment using artificial stomatal openings which expelled each gas respectively. Researchers were able to make these conclusions based on the obvious accumulation of the nematodes on and within artificial stomates expelling CO. This suggests these nematodes are able to locate stomata based on chemical sensing.
In September 2018, researchers at the University of California developed artificial cells that can kill bacteria. The cells were engineered from the bottom-up — like Lego blocks — to destroy bacteria.[18][19][20]
Polymersomes can be used to make an artificial cell if hemoglobin and other components are added. The first artificial cell was made by Thomas Chang.
The German pathologist Rudolf Virchow brought forward the idea that not only does life arise from cells, but every cell comes from another cell; "Omnis cellula e cellula".[59] Until now, most attempts to create an artificial cell have only created a package that can mimic certain tasks of the cell. Advances in cell-free transcription and translation reactions allow the expression of many genes, but these efforts are far from producing a fully operational cell.
Some cities require that cell sites be inconspicuous; they can be blended with the surrounding area or mounted on buildings or advertising towers. Preserved treescapes can often hide cell towers inside an artificial or preserved tree. These installations are generally referred to as concealed cell sites or stealth cell sites.